Blogs / Bad Astronomy

M81 and M82 are bright nearby galaxies; you can spot them with binoculars easily in the northern sky, and they are a mere 12 million light years from us (for comparison, the Milky Way Galaxy is 100,000 light years across, so if you think of the Milky Way as a DVD, M81 and M82 would be about 14 meters away). These two galaxies interacted a couple of hundred million years ago, and the gravitational interaction drew out long tendrils of gas (which is very common in colliding galaxies).

Astronomers examined this bridge of material using Hubble, and found clusters of stars in it. That was totally unexpected; the gas was thought to be too thin to form stars! Amazingly, many of the stars are blue, indicating they are young (blue stars burn through their fuel much more quickly than redder stars. This means that the gas is still forming stars, even 200 million years after the collision!

In the image below, almost all the stars you see are young blue stars formed in the aftermath of that titanic collision. The reddish stars are stars in our galaxy, and the bigger objects are distant background galaxies.

Most likely, the stars formed when turbulence in the tendril caused local regions of denser gas, which could collapse to form stars. Before these observations, it wasn’t really thought it was possible to form stars in the regions between galaxies, so this is an interesting new find.

When a star explodes, the expanding gas, will, over thousands and even tens of thousands of years, mix with the pre-existing gas between the stars. When it does, they interact and form sheets, ribbons and filaments.

Can’t imagine it? Good thing the National Optical Astronomy Observatory has a gorgeous picture of it:

This image shows just one small section of the Veil Nebula in the constellation of Cygnus. It was made by my buddy Travis Rector, whom you may remember from my Top Ten Astronomy Pictures (he put together the image of galaxy IC 342). The picture is comprised of two pointings of a 64 megapixel camera sitting on the back end of a 4-meter telescope. I don’t know about you, but my 5 megapixel camera suddenly looks a little weak.

This was a press release today, and I was just chatting with Fraser and Pamela about it. There’s no real news affiliated with it, but sometimes I think it’s OK just to release a pretty picture and say, "Look! Hawesome!"

Forgive these rather long expository posts; I’ll get to real astronomy very soon, trust me. But I am reporting on what’s happening here in the order it occurs.

A fixture at these AAS meetings are what’re called Town Hall Sessions, where high-ranking members of some community come and talk to the astronomers. Directly after Mike Griffin’s talk, NASA held a Town Hall. Speaking were Alan Stern, NASA’s Associate Administrator for Science, as well as several other NASA folks.

Stern gave an interesting talk. There has been a lot of worrying in the astrophysics community recently that money is being taken away to pay for other things (like, future observatories being defunded to pay for going back to the Moon - and these were legitimate complaints, I’ll add).

However, Stern pointed out that that cost overruns across the Science Mission Directorate of NASA were almost $5.8 billion over five years. That’s nearly twice the amount of money taken out of SMD to fund other programs. In other words, if we could control costs, we wouldn’t have to worry nearly as much about funding cuts or funding transfers.

A few years ago, I heard Griffin say that these aren’t cost overruns, they are proposal underfunds. In other words, the teams proposing missions don’t ask for enough money. Shocker! That’s the environment of the way we fund projects: when you compete for missions, it’s very tempting to ask for less money than you need so that you might look more frugal (or at least look like you run a tighter ship) than your competitor. I’ll say that having been on several proposals for missions, I’ve never seen this personally, but I can see how it can happen easily enough. And it clearly does; many missions run overbudget. Sometimes that’s honest; it’s impossible to know all the troubles you’ll have later in the mission that will delay launch and cost more money. Bt it sure does sound like sometimes, a mission budget may be lowballed on purpose.

Stern’s talk was a stark contrast to that of Mike Griffin’s, though in essence he said many of the same things. Stern was far more positive, being clear that the astronomical community needs to work with NASA to keep costs down, and with that cooperation we can aid NASA hugely. I liked his attitude of cooperation more than Griffin’s attitude of chastisement. I think we need both attitudes, at least some mix of them. But I’d like more of Stern’s on the balance.

And I’ll leave this with some cool news: NASA recently announced that they will start accepting proposals for a new science mission. They ask teams to send in their Notice of Intent, that is, a letter stating the team will be sending in a proposal. When they made that announcement, they received 85 Notices of Intent. Clearly, scientists still have a lot of trust and support for NASA. I love to hear that; it takes years to get a mission put together and it’s good to see not only that NASA is opening up more mission opportunities, but also that that astronomy community is jumping on those opportunities.

NASA Administrator Mike Griffin gave a talk giving an overview of NASA and astronomy today.

His theme was clear: NASA is doing well, but people — especially astronomers — have to understand that the budget is limited, and there is only so much to go around. To fund one thing, we have to cut another. This is a truth we must face.

He started off talking about Hubble, Chandra, Spitzer, and Swift. It was a little funny to hear about the astronomy NASA has done, since the audience was intimately familiar with it all, but it’s nice to hear anyway… especially since he also gave an overview of what’s to come in the next few years. Dark energy missions, observatories dedicated to look for planets around other stars, and more are on the horizon.

The Astrophysics budget in NASA is more than a billion per year, and has been for years. Griffin noted that amount is larger than the entire Japanese space budget. We astronomers are all too aware of how much money this is, of course, and how wonderful a position we have that our government funds it at this level. Astronomers have spent years working with the government on this, so it’s a fantastic synergy.

Griffin was pretty clear on how important this work is, and how it inspires us, and especially our children. But of course it comes with a literal price. NASA has a fixed budget, and has other priorities as well. An instrument (an alpha magnetic spectrometer or AMS, for those keeping score at home) was designed to go on the space station, and promises were made to our international partners to build, launch, and install it. It would cost $400 million to put the AMS on the ISS. To pay for this, money must come from elsewhere, and Astrophysics is a pretty fat target.

SIM, the Space Interferometry Mission, will look for planets — some potentially Earthlike — around other stars. SIM has passed all its technological hurdles, and has been deemed ready to be built. However, NASA cannot support at the same time both SIM and other big missions like the James Webb Space Telescope, the successor to Hubble. JWST eats up 60% of NASA’s astrophysics budget (holy Haleakala!) so we need to be careful on not just what gets funded, but when.

Griffin has made it clear he thinks we need to hold off on SIM while other missions are developed, but Congress has mandated work start on SIM. This doesn’t happen in a vacuum, Griffin said; he basically accused astronomers of advocating SIM to Congress, a mission that will now threaten other missions. He’s quite possibly right; astronomers get a lot, but we want a lot more, too. Still, I suspect that when astronomers advocate to Congress for a mission, it’s in the hopes that Congress will actually increase the budget enough to accommodate it. That would be a naive attitude. If they do this knowing full well it will impact other missions, well then, that’s politically naive to the point of self-mutilation. I’d be curious to hear more about this story, and find out what is actually going on.

Griffin continued his somewhat exasperated talk; saying that manned missions took a serious hit after Columbia, and saying in a somewhat sideways manner that perhaps many astronomers don’t care. He has a point again; many scientists are actively against manned flight, seeing it as a waste of money when robotic explorers can do so much. Mind you, this is true in some cases (like basic scientific exploration of Mars and the Moon, for example), but it is naive, of course. Manned spaceflight will always be inspirational, especially to young children, and I think it has its place. The problem is that manned flight costs so much more than unmanned, and it would be nice if Congress could figure out how to balance the two in NASA’s budget.

He pointed out the space station is a big part of NASA’s mission, and that must be recognized. To ignore it while discussing NASA is futile. Again, he’s right: many astronomers — myself included — think the ISS is a waste of money. However, we must face the truth that the ISS is a fact of life for NASA, and must be funded and completed. It will do no good to complain that he money is being thrown away… at least, it’s useless to complain now. It’s too late for that. However, there will be future missions, and I think we need to examine these missions very critically to make sure they don’t turn into more space station-like missions, white elephants eating up hundreds of billions of dollars for no focused value.

He ended by pointing out that we must all hang together or we will surely all hang separately. What he is trying to tell us is that NASA will do what it can for science, and for astrophysics, but it will only be able to do what it can. This is good advice, for both astronomers and NASA officials. We must all take a broader view.

However…

My own personal opinion: one of the things I like about Griffin is his forthrightness. He says what’s on his mind, and that’s refreshing. I agree with him on many points, and disagree on many others. It may hurt to hear the truth, but I try very hard not to let that stop me from hearing it. In many ways, then, I was happy to hear Griffin’s talk, although I must admit that his exasperation does seem a little peevish as opposed to being constructive. Having said that, I wouldn’t take his job on a bet (or even for a good fraction of NASA’s budget). He must have people advocating a dozen such divisions other than Astrophysics, and we are but one of the cacophony of voices he hears. Still, when speaking to a crowd of advocates, implying, or even outright saying, they are being childish on some topics won’t help… even if he’s right.

There’s politics in government, of course, but anytime you get a group with more than three people in it, there are politics there as well. I hope that the politics I saw here today don’t interfere with the greater good of both science and NASA.

I am reporting from the American Astronomical Society meeting in Austin, Texas. I’ll be attending press conferences and talking to astronomers, and blogging madly about all this.

Right after the Hubble press conference, astronaut John Grunsfeld — who is the leader of the astronauts’ Hubble extravehicular activities — showed us a spacesuit glove. I tried it on; it’s too small for my abnormally long fingers, but I could still see how hard it would be to work with one of those things strapped onto your hands.

When they service Hubble, they’ll be using a special device to take off and capture the many, many screws of off STIS. I asked him what would happen if he lost one…

I am reporting from the American Astronomical Society meeting in Austin, Texas. I’ll be attending press conferences and talking to astronomers, and blogging madly about all this.

Unlike most satellites orbiting the Earth, the Hubble Space Telescope was designed to be periodically upgraded, serviced by the Space Shuttle. This allows astronomers and engineers to keep the technology on the grand old ’scope up to date. This year, NASA plans on servicing the Hubble Space Telescope for the very last time. A full suite of upgrades and fixes are planned, and it’s a very ambitious mission. In fact, it’s the only non-space station International Space Shuttle flight planned; every other Shuttle flight will be to help construct the ISS.

The last time Hubble was serviced was in 2002, so it’s high time for it to be renovated.

At this first AAS press conference, the servicing mission was reviewed. Astronaut John Grunsfeld gve the meat of it; he will lead the activity on the Shuttle. This is his third mission to Hubble, adn his fifth to space.

The major upgrades in this mission are the installation of two cameras — the Wide Field Camera 3 and the Cosmic Origins Spectrograph. Two cameras already on Hubble will be repaired - the Advanced Camera for Surveys (ACS) and the Space Telescope Imaging Spectrograph (STIS). New parts to be installed include six new gyroscopes (which keep the telescope pointed once it locks onto a target) six new batteries, a new Fine Guidance Sensor (which tells it precisely where it’s pointed), new outer blanket (insulation) layers, and a Soft Capture Mechanism.

New Cameras

WF3: Hubble itself is a telescope, able to take light from the sky and bring it into a sharp focus. There are several cameras on the back end of the ’scope, each with their own capabilities. One of the original Hubble cameras was the Wide Field Camera. It was a great instrument for its time, but as tech progressed the detectors got better, so it was replaced with WFPC2 a few years later. The original camera was brought to Earth, and the bus (the framework) was reused to put in all new optics and electronics… creating the WFC3, the most advanced camera to ever go on board Hubble. It will vastly increase the capabilities of Hubble, allowing deeper images to be taken, which manes it will see fainter objects than ever before.

COS: Spectrographs break light up into each individual wavelengths (that is, colors; think of it like a rainbow), which can reveal all sorts of cool information about astronomical objects, including their temperature, composition, distance, rotation, and lots of other things that allow astronomers to understand objects trillions of miles away. COS will do this with ultraviolet light, where hot objects dominate: massive stars, exploding supernovae, gas clouds where stars are being born, and far more. COS will give us far more detailed spectra than we have been able to do before. This must be done from space, because UV light is almost totally absorbed by the Earth’s atmosphere.

Cameras to be fixed

STIS: When it was installed, STIS was the most technically advanced camera ever flown in space. It could take images in ultraviolet, visible, and infrared light, and it also could take spectra: it After several years of amazing service, a circuit board on STIS shorted out. In this mission, the astronauts will have to remove 111 (yes, one hundred eleven) tiny screws to open up the camera and replace a fried electronics board. This is an incredibly difficult task; the screws are small (bigger than watch screws, but not by much) and were not designed to be removed at all, let alone using astronaut gloves.

ACS: This camera was installed on Hubble in 2002, but it an electronic short killed it a few years later. Much like STIS, there are many dinky screws to remove, keep track of, and then reinstall. ACS takes amazingly beautiful (and of scientifically interesting) images, and has a key component called a coronograph. If you want to see something dim (say, a bird flying in the sky) next to something bright (say, the bird is near the Sun), you block the bright light so you can see the faint one. That’s what a coronograph does; it blocks the bright light from a star so that we can look at the environment around the star. ACS can point at bright young stars and see the disk of gas and dust that still surround them, allowing us to investigate what forming solar systems are like.

Components to be replaced:

Gyroscopes are among the few moving parts of Hubble. Once Hubble locks onto a target, the gyroscopes keep it fixed there. These wear out after a few years, and when all is working well there are at least three gyros working, and three are kept as backups. Right now Hubble has only one four working gyros and is operating on two; the others have since died. If that last one goes, Hubble will have to be shut down. All six gyros will be replaced on this mission.

Batteries: Hubble runs on solar power, but uses batteries when it is in the Earth’s shadow for roughly half its orbit. Over time, batteries lose their ability to hold a charge, so new ones will be put on board; it’s the only time they will have been replaced.

Fine Guidance Sensor: these are small telescopes in their own right, which lock onto a bright star with incredible accuracy and tell Hubble when it is pointed accurately at its target.

Insulation blanket: Every time Hubble moves into or out of the Earths shadow, the amount of heat it absorbs from the Sun changes dramatically, and that can strongly affect the cameras on board; as the metal expands and contracts it can change the pointing and focus of the cameras. The insulation blanket helps minimize this. Over time the blanket gets damaged from solar radiation, and will be replaced.

Soft Capture Mechanism: As time goes on, drag with the very thin atmosphere a few hundred miles up lowers Hubble’s orbit. If we do nothing, Hubble will re-enter the atmosphere and burn up in an uncontrolled manner. I doubt anyone wants a multi-ton 8 foot piece of glass falling on their house. The astronauts will attach a mechanism on the bottom end of Hubble so that an unmanned rocket can rendezvous with it, and bring Hubble down in a controlled manner over the Pacific ocean, minimizing the risk. I’d love to see us either reboost it again or bring it back down to put in a museum, but there is no money to boost it and keep using it forever, and it’s too heavy to bring down safely. And let’s face it: every space flight is risky, and sending astronauts up just to bring Hubble back is too big a risk.

Comments:

I’m personally torn about this mission. I’m really glad NASA is finally reservicing Hubble. I used it for a decade, working with it even before it launched. I got my PhD with Hubble data, and then worked on STIS for several years. I am really hoping they can bring my old camera back up to speed; I wrote a lot of software for STIS and I’d like to see it get more use!

But I’m sad it’s the last mission to Hubble. There just isn’t enough money to keep Hubble working forever, and even though this mission is to keep the ’scope alive for a few more years, it’s hard not to look at it with a little bit of wistfulness. Hubble changed the way the public sees the Universe, showing everyone just how beautiful and awesome astronomy is. But I’m also happy, thrilled, that we’ll get a few more years out of the lady, and I hope — and there’s plenty of experience to back this hope up — that we’ll get a lot more beauty, a lot more science, and a lot more surprises from Hubble in her remaining years.

After all as Alan Stern, NASA’s Associate Administrator of Science (NASA’s top banana for science) said, the goal of this mission is:

When the astronauts leave Hubble for the last time, it will be at the apex of its capabilities– better than it ever has been before.

What more can we ask for?

Sorry about the lack of blogging yesterday me droogs. I am now in Austin with Pamela and Fraser at the American Astronomical Society meeting, and things’ll be getting started here in a few minutes… we’re hitting the ground running with a press conference on Hubble, and I’ll have something up about it soon.

Everything Pamela, Fraser, and I write will be mirrored at the Astronomy Cast site, so you can go there for one-stop shopping if you like.