On October 28, 2015 Cassini passed below (above?) the south pole of Enceladus at an altitude of 49 kilometers. The probe was flown here in order to get a taste of the water-ice particles that are streaming out into space from Enceladus’ suspected sub-surface ocean in this location. This is the lowest pass Cassini has made through the alien ocean geyser.
This was done in order to help scientists understand the nature of the ocean, how close to the surface it might be, and if the water contained in it could accommodate life. Also of particular interest, the Cassini team is looking for a particular chemical signature of hydrogen that could support the theory that Enceladus has hydro-thermal vents heating water deep in the moon’s ocean.
It’s important to note, however, the instruments Cassini carries on board can characterize the chemical composition of any particles it encounters, but it doesn’t have the ability to directly test for life.
The detailed analysis of the tiny water droplets that Cassini caught as it flew through the plume is now underway (with full results a few weeks away), but some images of the fly-by have already been sent back. And as we’ve come to expect from Cassini, they’re spectacular.
The south polar region of Saturn’s active, icy moon Enceladus awaits NASA’s Cassini spacecraft in this view, acquired on approach to the mission’s deepest-ever dive through the moon’s plume of icy spray. The wavy boundary of the moon’s south polar region is visible at bottom, where it disappears into wintry darkness. CREDIT: NASA/JPL-Caltech/Space Science Institute
A RAW and unprocessed image from Cassini as it flew towards the icy plume at Enceladus’ south pole. CREDIT: NASA/JPL-Caltech/Space Science Institute
During its closest ever dive past the active south polar region of Saturn’s moon Enceladus, NASA’s Cassini spacecraft quickly shuttered its imaging cameras to capture glimpses of the fast moving terrain below. This view has been processed to remove slight smearing present in the original, unprocessed image that was caused by the spacecraft’s fast motion. CREDIT: NASA/JPL-Caltech/Space Science Institute
Following a successful close flyby of Enceladus, NASA’s Cassini spacecraft captured this artful composition of the icy moon with Saturn’s rings beyond. This view looks towards the trailing/anti-Saturn side of Enceladus. North is up. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Oct. 28, 2015. The view was acquired at a distance of approximately 171,000 km from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 141 degrees. Image scale is 10 km per pixel. CREDIT: NASA/JPL-Caltech/Space Science Institute
Whatever you call it, Asteroid 2015 TB145 was discovered only three weeks ago – on October 10, 2015 by the University of Hawaii’s Pan-STARRS-1.
It is just over half a kilometer in diameter (600 meters) and made its closest approach to Earth today at 1 p.m. EDT. It’s distance to Earth at its closest point was 486,000 km – or about 1.3 times distance from the Earth to the Moon.
Fittingly, since today is Halloween, if you rotate the images just right the comet/asteroid does sort of look like a skull. Spooky.
The above images were created by NASA using radar data from the 305 meter Arecibo Radio Observatory in Puerto Rico. The images were captured October 30, 2015.
Astronomers have determined, primarily by examining the amount of light the object reflects, that it is likely a dead comet. That is to say it’s a comet, but over the eons it has lost its volatile materials, and so is now reasonably dark and doesn’t produce the typical sign of a comet: a tail. This is why it was initially thought to be (and named) an Asteroid.
In any event, observatories around the world are pointed at it to learn everything we can about it’s composition and orbit. It also underscores the need to keep an eye on the sky, since this is a big piece of rock, reasonably nearby in the grand scheme, and we only found it three weeks ago.
Here’s a great announcement. One that “confirms a great future for Canada in space for years to come,” in the words of Canadian Industry Minister James Moore.
I chatted with Jerry Agar on NewsTalk1010 about the news
Today it was announced that Canadian Astronaut Jeremy Hansen, along with fellow Canadian astronaut David St. Jacques, will have the opportunity to fly to and work on the ISS within the next decade as part of the Government of Canada extending funding to the ISS all the way to 2024. One of the flights will be before 2019 and the second prior to 2024. Who flies when will be determined in collaboration with ISS partners in the months ahead.
The Canadian funding will be in the neighbourhood of $350 million total, which is in line with current funding for the Canadian Space Agency’s ISS operations of about $83 million per year.
This money funds operations at the Canadian Space Agency, astronaut training, cost of launch, supplies and scientific equipment to operate the ISS, public outreach, and more.
Canada is also the third country to commit funding to continue ISS operations up to 2024 (following the USA and Russia) – extending it from the originally planned 2020. With the three largest ISS partners now committed, the next decade of ISS operations is likely secure. I also speculate that other nations will join the 2024 extension as there are currently 14 nations working together to operate the ISS, committed up to 2020.
It is also interesting to consider this: by 2017 NASA will again have its own ability to launch people into space, ending reliance on the Russian Soyuz spacecraft ever since the Space Shuttle stopped flying in 2011. This means that David and Jeremy could be the first Canadians to fly either the SpaceX Dragon V2 capsule or the Boeing CST-100 capsule, which are both currently under construction. It is also possible they’ll still launch on the Soyuz, but considering the projected budget advantages of the two new US-designed spacecraft, I’d imagine the Canadian Space Agency will go that route.
It’s also possible that Jeremy, as a CF-18 pilot prior to becoming an astronaut, could be assigned to a crew as the pilot for a future mission.
David was a medical doctor prior to becoming an astronaut – and medical experiments are a high priority for ISS research – so I expect he would be a very welcome addition to any crew as well.
Of course what or when their missions will be is speculative, but it is exciting to consider the possibilities.
The announcement today also included renewed funding for MDA to maintain the Canadarm2 and DEXTRE robots currently in operation on the ISS. (Read more about Canadian space robotics here.) Additionally, four new Canadian science experiments will be flying to the ISS this fall. And the Government of Canada will invest nearly $2 million to continue the work being done on Mars by the Canadian X-Ray Spectrometer on the Mars Science Laboratory, aka Curiosity Rover.
That’s all very exciting!
The work in space continues to inspire and improve life on Earth every day. This is a great forward-looking investment in science and the economy. I’ve written at length about the importance of investing in space before, here and here for example.
I’ve also had the opportunity to talk with Jeremy a few times, and David a couple times as well — each time they have been generous, open, and encouraging. I couldn’t be happier for their opportunity that awaits!
On one such occasion in May 2013 on the eve of Chris Hadfield’s return to Earth from the International Space Station, Ryan Marciniak, Paul Delaney, and I chatted with astronaut Jeremy Hansen on an episode of York Universe. He offered insight on what a visit to the ISS would be like, romanticize about one day maybe walking on the Moon or Mars, the rigours of training, and wise words for any young person contemplating their future – either as an astronaut or otherwise.
It’s also fascinating to hear Jeremy talk about the chance to “one day” be assigned to a flight — knowing that now today we’re taking one big step closer to that becoming a reality.
And for a little bit of a different look on Canada’s astronauts – namely having fun running around Toronto last year – here is the video from the Amazing Canadian Space Race, featuring Canadian Astronauts Jeremy Hansen and David St. Jacques in September 2014:
• Updated: May 8, 2015 @ 11:30 a.m. EDT (15:30 UTC).
• Tracking data from USSTRATCOM indicates Progress 59 burnt up May 8, 2015 at 2:20 a.m. UTC, +/- 1 minute.
• Progress entered the atmosphere off the west coast of southern Chile at a distance of 1,300 to 350 km.
• It is possible some pieces of debris survived re-entry, and could have landed anywhere from hundreds of kilometers off the west coast of Chile, to hundreds of kilometers off the east coast (meaning some could have fallen on land).
• At time of this writing, there are no reports of re-entry being sighted nor any debris being located.
• The Progress’ Soyuz rocket launched April 28 on schedule with the unmanned cargo ship carrying 2,357 kg of cargo to the International Space Station.
• About nine minutes after launch, as Progress separated from the Soyuz, the cargo ship failed to activate and communicate with the ground as expected.
• Data from Progress showed the fuel system did not pressurized and multiple telemetry sensors required for ISS docking failed.
• Video downloaded from Progress showed the spacecraft in a spin.
• Tracking data showed nearly 50 pieces of spacecraft debris in the vicinity of Progress while in orbit, though the precise nature of the debris is unknown (it could have been debris from the upper stage of the rocket or Progress itself).
• The six crew on board the ISS are in no danger as a result of the lost cargo delivery; they have ample supplies on board for many months.
• The next two cargo deliveries to the ISS are set for June (SpaceX Dragon, CRS-7) and August (JAXA, HTV-5).
• The investigation into this incident is currently focusing on the third stage of the Soyuz rocket.
Map showing the location of Progress’ decay position according to USSTRATCOM as well as the Russian Federal Space Agency (note Roscosmos appears to have misjudged re-entry by about 15 minutes early). Image Credit: Spaceflight101
The launch of Progress 59 (M-27M) went off smoothly at 07:09:50 UTC on April 28 from Baikonur Cosmodrome in Kazakhstan. The unmanned Progress resupply ship was atop an upgraded Soyuz 2-1A rocket, the second ISS resupply flight to make use of the upgraded rocket (the older version, the Soyuz U, had been in service since 1973). Progress 59 was being launched on an express, four hour flight to the ISS, with a fallback two day rendezvous option.
Eight minutes, 48 seconds after launch with Progress reaching its preliminary orbit, it separated from the third stage of the Soyuz rocket. It is now believed that trouble began around this time.
After separation, Progress was designed to deploy navigational antennas, collect flight telemetry, and pressurize the propulsion system manifolds. As ground controllers struggled to maintain contact with Progress, it appeared that systems were not functioning correctly on board the spacecraft.
On subsequent passes within range of ground communication stations, Russian controllers attempted to send commands to spacecraft and download data. Progress has refused commands from the ground and has been unable to provide much useful telemetry data, though it did downlink television video data successfully Tuesday morning and supply data showing that multiple telemetry sensors have failed. The fact that the command/telemetry system and the TV system uses different downlink paths has been suggested as the reason that one system is able to function while the other does not.
The downloaded TV video showed the spacecraft in a 60° per second spin, or tumble. Causes for this could be a stuck thruster, separation from the Soyuz not being clean, or possibly a system leak.
Tracking data also reported that Progress was in an orbit that is more elliptical than intended (data showed the orbit to be 193.8 by 278.6 km, versus the intended 193 by 238 km orbit). This suggests the Soyuz rocket may have slightly over-performed, though does not immediately account for the Progress’ failures. However, it has been speculated an improper shutdown of the Soyuz third stage engine prior to Progress separation may be the culprit.
More recent tracking data also indicates there is debris present in the vicinity of Progress, bolstering the possibility that the Progress/Soyuz separation was botched. It is unknown though whether the debris is from Progress or the third stage of the Soyuz rocket body.
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Despite the best efforts of mission controllers in Moscow and Houston, they were unable to salvage Progress 59 and the craft re-entered the Earth’s atmosphere uncontrolled on May 8, 2015 at 2:20 a.m. UTC, plus or minus one minute according to US military tracking. Based on this time frame, the re-entry took place off the west coast of southern Chile.
If the re-entry took place at the earliest part of the window (2:19 a.m.), Progress would have been 1,300 km off the coast. If decay occurred at the end of the window (2:21 a.m.) Progress would have been 350 km west of Chile.
Even though re-entry was uncontrolled, there was little danger to anyone on the ground. The Progress vehicles are designed to be disposable and burn up upon re-entry. Still, it is possible that some of the heavy and dense parts of the spacecraft could have survived – namely the docking ring and propellant tanks. Any debris that did survive re-entry could be scattered from several hundred kilometers off the west coast of Chile to severl hundred kilometers off the east coast – nearly to the Falkland Islands. This area also includes land in southern South America.
At this time, there are no reports of anyone witnessing the fiery re-entry or finding any debris on land. It’s very unlikely that any debris that landed in water would be found.
A pass of Progress 59 captured from the ground in Buenos Aires a couple hours prior to re-entry.
It is also important to note that the six crew currently on board the ISS are in no danger. The crew has ample supplies on board the station to survive productively for many months. However it should be expected that the cargo manifests for two upcoming ISS cargo flights will be adjusted to make up for higher priority cargo lost on this flight.
The next scheduled cargo flight to the ISS is a SpaceX Dragon capsule. It’s currently scheduled to launch on June 19, 2015 from Florida on mission CRS-7. Following CRS-7, a Japanese Space Agency (JAXA) HTV cargo ship is set to launch in August on mission HTV-5. There is also presently a Dragon docked with the ISS as mission CRS-6; it will depart the station and land back on Earth in mid-May.
Of concern for future flights, including manned launches, is the commonality between the Progress launch vehicle and the rocket used to launch Soyuz TMA capsules – which carry crew to the ISS. If there has been a problem with the common Soyuz upper stages, that problem would have to be addressed prior to use on future missions. Problems with the Soyuz third stage are currently being investigated as the cause of the Progress 59 failure.
Canadarm2 catches a visiting SpaceX Dragon cargo capsule at the International Space Station. (Credit: NASA)
As part of a special two-part special looking at STS-100 and the installation of Canadarm2, I conducted interviews with the Canadian Space Agency Flight Controller Supervisor Mathieu Caron and Canadian Astronaut Chris Hadfield. Part one of the special with Mathieu Caron aired April 27, 2015 (listen to the segment here) and part two with Chris Hadfield aired on May 4, 2015 (listen to that segment here).
York Universe airs live every Monday at 9:00 p.m. ET (1:00 a.m. UTC, Tuesday) on Astronomy.FM – the voice of astronomy on the internet.
STS-100 was a flight of the Space Shuttle Endeavour from April 19-May 1, 2001 (11 days, 21 hours). The flight was commanded by Kent Rominger, piloted by Jeffrey Ashby, and carried five Mission Specialists: Chris Hadfield (CSA), John Phillips, Scott Parazynski, Umberto Guidoni (ESA), and Yuri Lonchakov (RKA).
It’s been suggested this flight was the pinnacle of Canada in space. And this is arguably true, though there have been several other significant Canadian missions to be sure: the launch of Alouette or Chris Hadfield commanding the ISS, to name only two possibilities. The point of this though is to highlight the importance of STS-100 to Canada and the international space community, rather than argue about which the ‘most’ important contribution is.
The primary goal of STS-100 was to deliver and install to the fledgling International Space Station the new robotic arm, Canadarm2. Along to head this effort was Canadian Space Agency Astronaut Chris Hadfield – and installing the next generation arm required two spacewalks for Hadfield and Parazynski. Hadfield’s EVA on STS-100 was also the first spacewalk in history for a Canadian.
In total, the pair spent 14 hours, 50 minutes ‘outside’ in order to accomplish the goal.
Chris Hadfield on the first Canadian spacewalk on April 22, 2001. (Credit: NASA)
Canadarm2 is 17.6 m (58 feet) long and has seven powered joints. It weighs 1,800 kg and is capable of moving payloads up to 116,000 kg!
It can be controlled from on board the ISS, or remotely from robotics stations at mission control centres around the world, including the CSA’s John. H Chapman Space Centre just outside Montreal.
Canadarm2 was (of course) based on the design of the Space Shuttle Canadarm, first launched in 1981 on STS-2. Canadarm (1) was 15.2 m (50 feet) long. In all five Shuttle Canadarm’s were built, with a redesign in the 1990’s to increase the arms’ ability to move larger objects to support ISS construction (the strength was increased by an order of magnitude, going from 332.5 kg up to 3,293 kg).
Towards the end of STS-100 once Hadfield and Parazynski had completed its installation, Canadarm2 was powered up for the first time in space on April 28, 2001.
And Canadarm2’s first objective? Link up with the Shuttle Canadarm to return the new arms cargo palette to Endeavour’s cargo bay. It was a remarkable Canadian robotic handshake in space.
The Canadian Handshake: Canadarm and Canadarm2 connect in space for the first time on April 28, 2001. (Credit: NASA)
Since then, Canadarm2 has been invaluable in both the construction and operations of the ISS – including catching visiting cargo spacecraft and docking them to the station on a regular basis. It is not an exaggeration to say that the ISS would not have been able to have been constructed without Canadarm2.
Look back at STS-100 with the astronauts who flew the mission:
Canadarm2 is able to move itself around on the ISS by making use of either the Mobile Transporter (a rail structure that runs the length of the ISS) or by moving end-over-end, sort of like an inch-worm, and grappling Power Data Grapple Fixtures that provide a physical connection as well as electrical and data connectivity. With these two methods within arm’s reach, Canadarm2 is able to be work from any location along the ISS’s main truss.
Canadarm2 has also since been joined on the ISS by a second Canadian robotic handyman: DEXTRE, which arrived in March 2008 on STS-123 (read more about DEXTRE here).
With these innovations – and others – Canada is making a name for being a leader in space robotics, and STS-100 surely cemented that reputation.
Canadian space robots: DEXTRE catches a ride at the end of Canadarm2 on the ISS. (Credit: NASA)
The Hubble Space Telescope was launched on April 24, 1990 – a quarter century ago! Since then (admittedly with a couple hiccups) it has been peering deeper into the cosmos than any telescope in human history. We have learned more about the origin of the universe, the makeup of galaxies, and distant worlds though Hubble’s eye – and with great effort from many researchers around the world.
Hubble is a joint project of NASA and the European Space Agency (ESA). Hubble weighs in at 11,000 kg, is 13.2 m by 4.2 m, and has a 2.4 m diameter primary mirror. Hubble coasts along in orbit at a cool 25,600 km/h at an altitude of 555 km above the surface of the Earth.
Hubble’s direct successor in space will be the James Webb Space Telescope, set for launch in 2018 – though Hubble is still expected to be in operation. Numerous next generation ground-based telescopes will also come online between 2020-2025, including the Thirty Meter Telescope (read in detail about TMT here).
To celebrate Hubble’s 25th birthday, the Hubble team released a new image from Hubble today: an image of the cluster Westerlund 2 and its surroundings.
This NASA/ESA Hubble Space Telescope image of the cluster Westerlund 2 and its surroundings has been released to celebrate Hubble’s 25th year in orbit and a quarter of a century of new discoveries, stunning images and outstanding science. The image’s central region, containing the star cluster, blends visible-light data taken by the Advanced Camera for Surveys and near-infrared exposures taken by the Wide Field Camera 3. The surrounding region is composed of visible-light observations taken by the Advanced Camera for Surveys. (Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), A. Nota (ESA/STScI), and the Westerlund 2 Science Team)
Even after 25 years, Hubble continues to impress with its images and scientific discovery to this day. For instance, Hubble data recently contributed to strengthening the hypothesis that Jupiter’s largest moon Ganymede has a massive subsurface ocean of liquid water.
One of the best videos I’ve been able to find that offers an overview of the Hubble mission is from the telescope’s 15th birthday, back on April 24, 2005. It’s worth a watch, and of course add another decade (!!) worth of discovery on top:
On top of several physical celebrations going on around the world for the occasion of #Hubble25, there is also a lot of great content on social media:
And remember a couple years ago when the Defense Department donated two better-than-Hubble space telescopes to NASA? Read here for that one.
It’s a big universe and we need all the eyes we can get to help unravel its mysteries.
The Canadarm on board The Space Shuttle Discovery releases Hubble in April 1990. (Credit: NASA/ESA)
And a fun (patriotic Canadian) fact: the last piece of hardware to come into physical contact with Hubble was the Canadarm on board the Space Shuttle Atlantis on mission STS-125 in May 2009, following the conclusion of Hubble Servicing Mission 4, the last mission to visit the telescope:
Canadarm lifts the Hubble Space Telescope out of the payload bay of Atlantis, moments before it is released into space following the successful repair mission of STS-125. (Credit: NASA)
The Thirty Meter Telescope (TMT) will help solve some of the deepest mysteries of the universe and will be the largest, most advanced telescope ever built when it opens.
TMT has also been in the news off and on for a number of years as the project has moved through its proposal and design phases, dating back to 2003.
But recently it has been in the news in a big way (particularly in Canada), as Prime Minister Stephen Harper and Industry Minister James Moore announced that the Canadian government would provide an additional $243.5 million (approx. $200 million USD) over 10 years in funding for the construction of the next-generation telescope.
This money will be spent primarily in three areas: construction of the metal frame for the telescope dome (to be built by Dynamic Structures Ltd.); Supplying the advanced adaptive optics system, a centrepiece of the TMT design (the National Research Council of Canada is managing this), and; operating costs.
Canada already contributed about $30 million during the design phase, and the Association of Canadian Universities for Research in Astronomy (ACURA) has played a significant role – alongside the University of California (UC) and the California Institute of Technology (Caltech).
What follows is a plain language overview of the TMT project and what the Canadian funding means for it.
A schematic of the Thirty Meter Telescope (Source: TMT).
The Thirty Meter Telescope will be, in short, the largest and most advanced ground-based optical observatory ever built when it is completed sometime in 2022.
The project is led by a consortium of UC and Caltech. Those two schools between them account for a 25% stake in the project. Japan is also on board with a 20% stake. Canada comes next, with the $243.5 million accounting for a 15-20% stake. China and India each have a 10% stake.
With Canada’s contribution in place, the TMT has achieved 80% of the capital funding required, and the team continues to negotiate with other potential partners to secure the remaining funds. Construction though is underway, with the ground-breaking that took place in October 2014 officially kicking it off.
There are whispers the U.S. will come on board via a National Science Foundation (NSF) grant, but as yet that hasn’t happened.
TMT will be built atop the Mauna Kea volcano in Hawaii, with an elevation of about 4 kilometers.
The observatories atop Mauna Kea, Hawaii include, from left to right foreground: the UH 0.6-meter telescope (small white dome), the UK Infrared Telescope, the UH 2.2-meter telescope, the Gemini Northern 8-meter telescope (silver, open) and the Canada-France-Hawaii Telescope. On the right in the background are the NASA Infrared Telescope Facility (silver), the twin domes of the Keck Observatory and the Subaru Telescope (Source: University of Hawaii).
In telescopes, size matters, and so the TMT’s primary mirror at 30m (98 feet) will be three times larger than the current largest, the Gran Telescopio Canaris (10.4m, opened in 2007) at La Palma in Spain’s Canary Islands. The extra diameter will provide TMT with ten times the light collection ability.
The same size comparison holds true for the twin W. M. Keck Observatories (10m each), which will coincidentally be TMT’s neighbours at Mauna Kea. And while second in size, Keck is often considered one of the most advanced optical telescopes currently in operation thanks to the highly advanced adaptive optics they were retrofitted with about a decade ago (more on adaptive optics later). Keck 1 opened in 1993 with Keck 2 following in 1996.
Another famous telescope – perhaps the most famous – is of course the Hubble Space Telescope, launched in 1990. TMT will have 144 times (!!) the light collection ability over Hubble’s 2.4m mirror. TMT will also provide about 10 times better image resolution.
The Horsehead Nebula (Source: NASA/Hubble Space Telescope). TMT will have 144 times more light collection and 10 times better resolution than Hubble.
Though by the time TMT is completed, there will be other kids on the telescopic block.
The Giant Magellan Telescope at Las Campanas Observatory in Chile will likely have opened – it’s currently looking to be completed in 2021. Though at 25.4m, the GMT’s rein as world’s largest telescope will be short-lived. Of course, 25.4m is nothing to sneeze at – it will still be 2.5 times larger than the present-day biggest.
Similarly, TMT will only be the world’s largest for a few short years. Sometime around 2024-2025 the European Extremely Large Telescope (don’t you love the naming convention for these bad boys?) is expected to be completed at the European Southern Observatory (ESO) in the Atacama Desert, Chile. The E-ELT’s primary mirror will be fully 39.3m in diameter.
These three mammoth ground telescopes – the GMT, TMT, and E-ELT – represent a generational leap forward in terms of size, technology, and ability to peer deeper into the cosmos than ever before.
As a scale comparison, imagine a professional baseball stadium. If the TMT were placed on the pitcher’s mound, the primary mirror would nearly fill the entire infield. The structure is also 22-stories tall.
But why does size matter so much?
It matters because the size of the mirror is directly proportional to the amount of light the telescope has the ability to collect. And more light means the telescope is able to produce sharper images and detect fainter objects, allowing the astronomers to see objects and detail that otherwise wouldn’t be possible.
In your own life, consider the difference between a point and shoot camera and a D-SLR. In some cases the D-SLR has a better sensor than the P&S, but not always. So why does the D-SLR capture better images (particularly in low-light), assuming an equivalent sensor? Because the optics in front of the sensor capture more light, allowing the shutter to fire faster, and in turn create a sharper image. (I realize this isn’t a complete analogy, but I hope it sheds some [pardon the pun] light on why size matters.)
But, if it’s so important to have telescopes collect the maximum amount of light, why haven’t they been built this large before? A couple reasons.
First, as it often boils down to, is money. Building large telescopes is expensive (both TMT and E-ELT come with a total price tag between $1 and $1.5 billion each). But money alone only really tells part of the story here.
The underlying basis for why telescopes haven’t been built this large before is the second reason: technology. The relevant advances in technology are similarly revealed mainly in two places: segmented mirrors and adaptive optics.
Segmentation allows huge mirrors to be broken down into smaller pieces, which in turn allows for more straight forward construction, transportation, maintenance, and so on – all of which reduces cost. Large mirrors are extremely difficult to manufacture, heavy to support, and challenging to move around. For instance, could you imagine a 30m single piece of glass being moved up the side of a 4km tall volcano in Hawaii, to say nothing of getting it to the island in the first place?
TMT has two additional mirrors: a secondary (3.1m) and a tertiary (elliptical, 3.5×2.5m). The secondary mirror is placed above the primary mirror in order to collect the light from it. The secondary mirror then reflects the light back down towards the tertiary mirror, which directs the light to the instrument suites.
The 30m TMT primary mirror will actually be made up of 492 smaller mirrors. Each hexagonal piece of glass being 1.4m long corner to corner, spaced 2.5mm apart, and 4.5cm thick.
It’s worth mentioning though that TMT won’t be the first telescope with segmented mirrors; it was pioneered on Keck, and since used on other observatories as well, including the Gran Telescopio Canaris. GMT, E-ELT, and the next generation James Webb Space Telescope (set to launch in 2018) will all employ segmented mirrors, too.
But mirrors, no matter how large, won’t do you much good if you can’t get a clear view of the sky – and that’s where adaptive optics comes in.
Any telescope on Earth has to contend with the atmosphere. That blanket of layers of fluid air, all swirling around and wreaking havoc on anyone trying to get a clear view of objects in space – particularly small or faint objects, which coincidentally are the focus of a great deal of astronomy nowadays.
Even with your own eyes you have to contend with atmospheric turbulence if you happen to go out stargazing. That twinkling you see when you look at stars? That is actually caused by turbulence in the atmosphere distorting the light as it passes through (the stars don’t really twinkle at all, at least not for the purpose of this discussion).
Telescopes have to contend with the same interference, and the result – if left uncorrected – are blurry images that lack the required level of detail that astronomers require to push the frontier of understanding further forward.
In order to overcome this, a way has been devised to correct for the atmosphere by manipulating the shape of the mirrors in the telescope. Two corrective mirrors in TMT will have highly precise actuators attached, which will be able to very finely reshape each mirror in real-time to create a clear image.
Left: The Galactic Center without adaptive optics (Source: Keck Observatory). Right: The Galactic Center and central black hole, Sgr A*, with adaptive optics (Source: Keck Observatory and the UCLA Galactic Center Group).
The physics behind this technology, in a nutshell, is that when light is disturbed by the atmosphere it creates a distortion in the light wave. By reshaping the mirrors, an opposite distortion can be created in the telescope, cancelling out the atmospheric distortion.
The TMT’s actuators are controlled by a computer system, which in turn relies on a system that measures atmospheric turbulence. This measurement is accomplished by either pointing the telescope towards a guide star or firing a laser beam into the sky to create an artificial star, which the telescope can then image in order to measure the distortion and correct for it in real time.
Similar to segmented mirrors, TMT isn’t the first telescope to make use of a new technology. Others, including Keck, have been retrofitted with these optical systems as the technology has developed over the last decade. TMT is however the first telescope ever to be constructed with adaptive optics as a core piece of the design.
TMT, many like other telescopes, is also being constructed in a place where the impact of weather (including cloud cover) will be minimized. In being on top of a mountain 4km above sea level, TMT will not have to deal with as much weather as it would at a lower elevation. Being higher up also helps to reduce some of the atmospheric distortions, as the thickest part of the atmosphere is the part closest to sea level.
An illustration of the Thirty Meter Telescope’s laser guide system (Source: TMT).
More light, higher resolution, clearer view – what do they hope to find?
Astronomers working on TMT will have a full suite of scientific instruments at their disposal, so the telescope will essentially be able to be used to study anything and everything in the cosmos. But in terms of ushering in new discoveries, in broad strokes, TMT will be ideal for studying the origin of the universe and exoplanets.
Understanding the nature of the universe, how it – and by extension we – ended up here is a significant question for science and astronomy to try to unravel. TMT will take full advantage of its massive mirror to peer back in time and capture the faintest light from the earliest moments following The Big Bang. By observing how ancient stars and galaxies formed, it will advance our understanding of why things are the way they are, and inform what the forces at work in the universe are today. TMT will also help to fill in gaps about the structure of the universe and the role that dark matter plays.
In terms of exoplanets, TMT will have the resolution to directly image worlds orbiting other stars. Using spectroscopic instruments, astronomers will also have the ability to measure the composition of those worlds – and whether they could be hospitable for life.
Thirty Meter Telescope will perceive things that no other human-built technology has ever been able to see. In so doing TMT will help to answer two of the most fundamental questions of our existence: how did we get here and are we alone.
The next generation of discovery is just beyond the horizon today, but it’s exciting to know as a human that before long, we’ll have it in our sights.
As a Canadian, it’s exciting to know that my nation will play a significant role in those discoveries and the benefits that follow from being a leader in research and technology development.
I joined Jerry Agar on Toronto radio station CFRB Newstalk 1010 to describe TMT. Listen here:
On the evening of March 11 (Eastern Time; it was the morning of March 12 in Kazakhstan) three astronauts returned home from the International Space Station in their Russian-built Soyuz TMA-14M spacecraft.
The astronauts were Elena Serova (RUS), Alexander Samokutyaev (RUS), and Barry “Butch” Wilmore (NASA). The landing went smoothly (as smoothly as a Soyuz landing can go, at least). They touched down vertically, and on schedule, on a cold and foggy morning in Zhezkazgan, Kazakhstan. It was about 30 minutes after sunrise.
And in the process of all that, NASA photographer Bill Ingalls took one of the most amazing Soyuz landing photos I’ve seen.
The Soyuz TMA-14M spacecraft is seen as it lands with Expedition 42 commander Barry Wilmore of NASA, Alexander Samokutyaev of the Russian Federal Space Agency (Roscosmos) and Elena Serova of Roscosmos near the town of Zhezkazgan, Kazakhstan on Thursday, March 12, 2015 (NASA/Bill Ingalls)
…and “amazing” doesn’t really do this photo justice. It’s majestic. It’s almost surreal (I actually looked twice when I first saw it to make sure it was indeed a real photograph, and not CGI).
The photo was taken from an aircraft just before the Soyuz disappeared into a layer of cloud on its journey to terra firma.
The astronauts had spent about six months on board the ISS as a part of the Expedition 41 and 42 crews.
To see some more photos from the landing (and download hi-res versions), check out this NASA Photoset on Flickr.
Over the past week or so we’ve seen a few stories regarding wet bodies in our solar system.
First, there was news about water on Mars. Now the news wasn’t so much that there was water on Mars, since that’s been pretty well understood for a while now (thanks in large part to the rovers Spirit, Opportunity, and Curiosity), rather how much water there was – and it’s plentiful to say the least.
Mars with a vast Northern Ocean (NASA/Goddard Space Flight Center)
Using land-based infrared telescopes (the ESO’s VLT and NASA’s Keck), NASA was able to measure the hydrogen isotopes in Mars’ atmosphere. The results indicate that Mars one had 20 million cubic kilometers of water – more water than is in the Arctic Ocean here on Earth today. Astronomers are also currently suggesting that the Martian water was contained, mainly, in one large ocean surrounding the Red Planet’s north pole. It would have covered proportionally more of the planet’s surface than the Atlantic Ocean does here.
Nowadays on Mars it’s bone-dry, quite a bit different from ~4 billion years ago. Current estimates suggest that Mars’ ancient ocean contained about 6.5 times more water than what is currently observed in Mars’ polar ice caps, meaning that a great deal was likely lost into space as the Martian atmosphere thinned 2-4 billion years ago (though some water could still possibly be trapped in a permafrost layer).
The next news item this week is regarding Enceladous, an icy moon of Saturn. Now again, we’ve understood for a while that this moon had a sub-surface ocean of liquid water, trapped beneath an icy crust, but the news this week is tantalizing: the possibility of active hydrothermal vents in the moon’s southern ocean.
Hydrothermal activity on Enceladous (NASA/JPL-Caltech)
Announced just a couple days ago thanks to data from the Cassini spacecraft, astrophysicists have been able to pinpoint the origin of tiny particles of silica that the spacecraft had been detecting in space as it orbits in the area. And the origin appears to be the southern ocean of Enceladous, a 10km deep body of water. How the silica particles form is a chemical process that takes places when ocean water interacts with volcanic activity on the ocean floor.
Precisely the same process has been observed in only one other place so far: right here on Earth. And on our world, hydrothermal vents are teeming with life.
Jump ahead to today, and NASA announces, using Hubble data, that the largest moon in our solar system has a sub-surface ocean of liquid water of its own.
Ganymede, a moon of Jupiter, has been theorized to have a sub-surface ocean since the Galileo probe visited the area in 2002. Shifting magnetic fields were a major clue indicating the presence of water, though the data at the time was inconclusive. But now a novel idea has allowed a team of astronomers to make use of the Hubble Space Telescope to study Ganymede’s shifting magnetic fields from afar: patterns in the moon’s auroras.
An illustration of Ganymede’s auroras (NASA/ESA)
By understanding how different materials impact magnetic fields, and how auroras present themselves through those magnetic fields, the astronomers were able to understand Ganymede’s make-up by studying the auroras using Hubble. What they found is an ocean of water. (Edit: not only an ocean of water, but a large ocean. Ganymede could have more water in its salty subsurface ocean than Earth does in all our oceans combined.)
With all this in mind – and not to mention other wet worlds, like Europa – the solar system is starting to look a little more damp than it was once thought to be. And here on Earth at least, it is well understood that anywhere you can find water – in any form – you are virtually guaranteed to find life as well.
So how do these discoveries impact the prospects for finding life in our solar system beyond Earth?
On Mars, I’m not sure it changes much. It’s been understood that the planet was once wet, that it was wet for hundreds of millions of years (if not a billion or more), and that the environment was once life-friendly. This week’s discovery drives home the idea that there was plenty of water, but I don’t know that it’s a game-changer.
For Enceladous, this is a significant discovery. Adding in the fact that geysers have been previously detected with organic chemicals, this icy world now has to be considered one of (if not the most) likely places to harbour life in our solar system. As we understand life, it needs water and an energy source; Enceladous now seems to have both. Contemplating what might be swimming around in that alien ocean right now is an intriguing thought. (Maybe Enceladous leap-frogs Europa as the target for a robotic submarine mission?)
Ganymede? Add it to the list of worlds with liquid water that require more study. (I would similarly categorize Europa.) Questions abound as to the nature of their oceans, if there is any volcanic activity, do they cover the entire world, and could there be life?
Clearly we have some exploring to do.
Astronauts on board the International Space Station capture an image of the Space Shuttle Endeavour prior to docking during the mission STS-130 in February 2010 (NASA).