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hubble space telescope

The More We Look…

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… the More We Find

Uranus
Sirius and its companion, from HST

Astronomy is a win-win proposition. You look at the sky with your naked eye and you see stars, planets, maybe a galaxy or two if you have the right observing conditions. You can always find something great to see.

If you magnify the view, you get to see more stuff that’s dimmer, farther away, and in more detail. It’s the science that keeps on giving, no matter what at what level you understand things.

If you REALLY magnify the view, say with a telescope like Hubble, you find things you’d never see with the naked eye. The top image is a view of the star Sirus, which lies just over 8 light-years away. It’s a blue-white star, and if you look at the belt of Orion and trace a line down from it to the horizon, you’ll run right into Sirius.

This star has a companion which is terribly difficult to see. It’s a white dwarf star called Sirius B. It’s not an easy star to spot because the brightness of Sirius overpowers the faint little glow of the companion. Hubble scientists managed to spot this Sirius-hugging little star by overexposing the bright star to get the dim glow of its little sibling.

Uranus Magnified
Uranus Magnified

The second image is a result of ongoing observations of the planet Uranus. HST scientists found a pair of rings (very thin, to be sure) circling the gas giant. We already knew that Uranus had rings, but this new discovery also tells us something is furnishing the dust that creates planetary rings. In thise case, a little moon called Mab that orbits the planet is most likely the source of the dust. Meteoroid impacts knock material from Mab’s surface, sending it into space. Ultimately it gets caught up into orbit around Uranus.

This is why I find astronomy a continual source of fascination. There’s always something new to find, to see, to learn. The universe is a great show-and-tell machine!

hst news, hubble space telescope

The Lazarus Telescope

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I have to hand it to the folks at the Space Telescope Science Institute. They’ve gone and done it again—bringing a critical part of the system back online after a wild few days of diagnosis. The Advanced Camera for Surveys (one of the telescope’s main “eyes” on the sky) suffered a power supply problem. They took it offline to avoid damage, did some quick tests, and managed to bring it all back late last week.

This episode brought back some memories of the first “fix” the telescope faced. Back when I was first in graduate school, HST had just been launched and scientists were eagerly awaiting the first views through its portals. The bad news of spherical aberration was terrifying, especially considering how much we’d spent on the thing, and how many peoples’ careers were entwined with the instruments onboard (including my advisor’s!).

HST on orbit
HST on orbit

Now it’s 16 years later and this venerable telescope is up there still ticking after a few refurbishment and repair missions, and cranking out incredibly great science. My first well-received book (Hubble Vision, now out of print in both editions, but I know you can still find it at Amazon) dealt with the technical issues and also the science as it started coming in.

HST left behind the “techno-flop” label a long time ago. I was glad to see those terrible times end because most of us who were on the teams or knew people on the teams knew that the scope could be made to work. It took a lot of ingenuity and sweat, but it got done.

A chart of HSTs targets. Solar system objects are shown as yellow dots; stars are blue; star clusters are orange; nebulae are green; galaxies are red; galaxy clusters are pink; and other targets such as the Hubble Ultra Deep Field and the Great Observatories Origins Deep Survey are the white dots.
A chart of HST's targets. Solar system objects are shown as yellow dots; stars are blue; star clusters are orange; nebulae are green; galaxies are red; galaxy clusters are pink; and other targets such as the Hubble Ultra Deep Field and the Great Observatories Origins Deep Survey are the white dots.

I was intrigued to see a chart of where HST has looked in the sky during its years on orbit. It seems to have looked literally in nearly every direction, and out to the most distant reaches of the observable universe. It has made more than 700,000 exposures and looked at more than 22,000 targets.

Despite the accomplishments, HST isn’t out of the woods yet. It is way overdue for a refurbishing mission. This week’s successful shuttle mission may put an HST “upgrade” mission back on the books. We can only hope. This is one darned fine instrument, and it deserves to be brought back to life as often and for as long as we can do it, or until the James Webb Space Telescope is a reality.