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)
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 Enceladus, 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 Enceladus (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 Enceladus, 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 Enceladus, 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; Enceladus now seems to have both. Contemplating what might be swimming around in that alien ocean right now is an intriguing thought. (Maybe Enceladus 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).
The Hubble Space Telescope (2009). Source: hubblesite.org
Last night after work I was having a beer with a colleague, and amongst various other things, we ended up talking for a few minutes about how long the Hubble Space Telescope will last. Specifically, we were discussing whether it will remain useful until 2018, which is when NASA is currently* planning on having the James Webb telescope ready. With the Space Shuttle fleet now retired, NASA doesn’t have any ability to perform maintenance on Hubble, replace parts, or make any required adjustments – so its days are numbered. At some point a gyro will fail, its alignment platform will lose its precision, and the imaging CCD sensors will have pixels die. It’s inevitable, but my colleague and I ended up agreeing that Hubble will likely remain functional in some way (though perhaps not in 100% condition) for the next six years.
* = I say “currently” because the James Webb telescope is presently four years behind schedule (and drastically over budget) so it is impossible for me to say confidently that 2018 will end up being the actual date that it’s ready.
Then today, we read the news that there are two telescopes (better than Hubble) just sitting around collecting dust in Rochester, NY.
It sounds almost unbelievable, but it’s true. The US Department of Defence has gifted two better-than-Hubble space telescopes to NASA.
And before we get into these two new ‘scopes, let’s take a little look back at the Hubble Space Telescope, which has allowed us to peer deeper into the cosmos than we ever have before.
The Hubble telescope is named after Edwin Powell Hubble, who was an astronomer in the early 20th century. Around 1920 he made the remarkable discovery that there were other galaxies beyond our own – a fact that we take for granted today (and of course he did other things too). Shortly after that, in the mid-1920s, the idea came about (from a German named Oberth) that it would be a good idea to put a telescope in space. Various ideas and designed followed over the next 30-40 years. Some satellites were launched (NASA launched the Orbital Astronomical Observatories in the 60s), however nothing yet on the scale of Hubble (which at the time was called the “Large Space Telescope”). In the mid 1970’s NASA started work on the Space Shuttle, which would be the new vehicle that would carry equipment into space – and allow (for the first time) service-calls while in orbit. Then, in 1977 the US Congress approved funding for one of the most sophisticated satellites ever built. This satellite was, of course, Hubble. Skip ahead a few more years to 1985, and Hubble was ready for launch. But in 1986 disaster stuck, with the loss of Space Shuttle Challenger, grounding the entire Shuttle fleet for two years and pushing back the launch of Hubble to April 24, 1990.
Since then? Well, the results speak for themselves:
And today, I repeat for a third time, the US Department of Defense (DOD) has gifted two telescopes – better than Hubble – to NASA. These two new telescopes were apparently built in the late 1990s by DOD contractors. Their mirror (the main component in determining the power of a telescope) is the same size as Hubble’s at 2.4m however their optics are much improved, including a field of view 100-times that of Hubble. These two new telescopes also have a maneuverable secondary mirror that Hubble lacks, allowing for higher-precision focusing. The design of the new telescopes also allows for a broader set of instruments to be installed.
The fact that these two new-found telescopes are better than Hubble shouldn’t be terribly surprising. When Hubble was designed and built, it was absolutely state of the art. But it was also designed and built in the 1970s and 80s. These two new telescopes were designed and built in the mid/late-1990s – and technology progressed a lot over those 20-30 years.
The surprising bit to me is two-fold: 1: The DOD had these two telescopes sitting in a warehouse in Rochester, NY collecting dust; and 2: The DOD, by openly gifting these telescopes to NASA, is willing to face intense scrutiny (and rightfully so) regarding what else they have sitting around collecting dust and how much money they have spent/are spending on projects like this (big kudos to the DOD for a willingness to bite that bullet, in the interest of helping out NASA, since the DOD could have just as easily scrapped these two beauty’s quietly).
Now onto the practical part of this story: NASAs budget and space lift capabilities, or lack thereof.
The two new telescopes need instruments. They need staff support. Scientific missions. Office space.
After all that, they need to be launched into orbit and deployed.
NASA simply does not have the capacity to do any of this, and likely won’t for another decade or so. Now NASA has undergone budget cuts lately, but to be fair a lot of this pain is self-inflicted: their previously referenced James Webb telescope has incurred such staggering budget overruns that it has forced the cancelation or delay of numerous NASA scientific missions.
NASA estimates that it could be 2024 until they have the ability to launch one of these new telescopes (launching the second one wasn’t even considered), unless money is no object, in which case they might be able to do it by 2018-2020 – which is still a rather long time line.
My solution? NASA should sell one of the new telescopes.
I’d be quite certain that either another space agency (European Space Agency, Japan Space Agency) or a commercial enterprise (SpaceX) would love to get their hands on one of these telescopes.
SpaceX’s Dragon docks with the International Space Station (May 25, 2012). Source: NASA
The benefits of selling one of them are numerous: NASA would get a cash injection right now that it desperately needs; the likelihood of both these telescopes being put into service would be greatly increased; the idea of creating some competition in the ‘discovery industry’ is a good one; one of them would probably end up in space faster than 2018-2024 that NASA projects; and by engaging another agency or company, NASA can help to inspire others to make amazing discoveries and help us to learn about the Universe and how we got here.
And of course NASA will still have the other telescope (and James Webb) to outfit, launch, and operate as their budgets allow.
I do expect the DOD would have something to say if NASA wanted to sell one of these new telescopes (it could very well be part of an agreement that NASA cannot sell them) as some of the design and technology inside is classified – and I’m sure the DOD would be hesitant to have outsiders crawling around inside them. Hopefully this problem can be overcome.
Whatever happens with these telescopes, in the very near future when I wake up tomorrow, I will live in a world where there are two more space-telescopes than I knew about yesterday – and that’s a good thing.
No, I’m not posting about Hollywood. I’m talking about an actual star. A star that is (or was) a lot like our Sun.
Astronomers spend a lot of time searching the cosmos for stars that are like our own, in hopes of being able to better understand how ours is working. You see, not all stars are created equal. Some are larger or smaller, some burn hotter or cooler, some will exhaust their fuel supplies over hundreds of millions of years, and others will burn for several billion years.
Without getting too technical, our Sun is on the larger and brighter end of the spectrum, though it is nowhere near as massive as some other stars in our stellar neighbourhood.
It is important to understand though that the Sun is not massive enough to trigger a Supernova explosion when its life ends in 4 or 5 billion years. Only the biggest stars end their lives so dramatically.
Why? Again, without being technical about it, as a massive star dies the outer layers of the star collapse in towards the core. These outer layers tend to be made of lighter elements, and so they essentially ‘bounce’ off the core and explode out into space. That’s what we call a Supernova.
Our Sun doesn’t have enough mass/gravity at it’s core to trigger a Supernova. The outer layers/lighter elements will not be drawn back towards the core as the Sun dies, and so they won’t have the opportunity to bounce/explode. Instead the Sun will slowly expand and cool, and will create a sort of planetary nebula (a cloud of reasonably hot gas and dust). Eventually the dust will clear, and just the core of the sun will remain. A very small, dense object, called a White Dwarf. And of course remember: this process takes millions of years, and won’t start for another ~4 billion years.
That takes us to this image:
A star that was like our own is in the planetary nebula stage of it’s life. Seeing this is exceptionally rare and important, as it helps us to better understand how own star will live its life.
Here is the description of that image from NASA:
“Within the Realm of a Dying Star
The NASA/ESA Hubble Space Telescope has been on the forefront of research into the lives of stars like our sun. At the ends of their lives, these stars run out of nuclear fuel in a phase that is called the preplanetary or protoplanetary nebula stage. This Hubble image of the Egg Nebula shows one of the best views to date of this brief, but dramatic, phase in a star’s life.
During the preplanetary nebula phase, the hot remains of an aging star in the center of the nebula heat it up, excite the gas and make it glow over several thousand years. The short lifespan of preplanetary nebulae means there are relatively few of them in existence at any one time. Moreover, they are very dim, requiring powerful telescopes to be seen. This combination of rarity and faintness means they were only discovered comparatively recently. The Egg Nebula, the first to be discovered, was first spotted less than 40 years ago, and many aspects of this class of object remain shrouded in mystery.
At the center of this image, and hidden in a thick cloud of dust, is the nebula’s central star. While scientists can’t see the star directly, four searchlight beams of light coming from it shine out through the nebula. Researchers hypothesize that ring-shaped holes in the thick cocoon of dust, carved by jets coming from the star, let the beams of light emerge through the otherwise opaque cloud. The precise mechanism by which stellar jets produce these holes is not known, but one explanation is that a binary star system, rather than a single star, exists at the center of the nebula.
The onion-like layered structure of the more diffuse cloud surrounding the central cocoon is caused by periodic bursts of material being ejected from the dying star. The bursts typically occur every few hundred years.
This image is produced from exposures in visible and infrared light from Hubble’s Wide Field Camera 3.”
Harrison lives in Ottawa, Canada. He works in politics and is passionate about many things, including space and exploration. He's worked for a national news outlet, managing the digital products, writing news, and appearing on air to talk about science, technology, and politics. In his spare time he enjoys astronomy, scuba diving, flying airplanes, photography, and sports.