Category Archives: planetary science

astronomy news, hubble space telescope, NASA, planetary science

A Million Peeks at Space

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Hubble Makes a Milestone Science Observation

This is an artist's concept of the extrasolar planet HAT-P-7b. It is a "hot Jupiter" class planet orbiting a star that is much hotter than our Sun. Hubble Space Telescope's millionth science observation was trained on this planet to look for the presence of water vapor and to study the planet's atmospheric structure via spectroscopy. Planets with orbits inclined nearly edge-on to Earth can be observed passing in front of and behind their stars. This allows for the planetary atmospheres to be studied by Hubble's spectrometers. Hubble's unique capabilities allow astronomers to do follow-up observations of exoplanets to characterize the composition and structure of their atmospheres. Courtesy NASA/ESA/G. Bacon (STScI)

Telescopes and the many different instruments that can be attached to them are made to look at the sky and ferret out the hidden mysteries, open our eyes to dim, distant objects, and reveal a million things we didn’t know were out there. Your backyard telescope can do this — as can the mightiest scopes on — or off — our planet.

The Hubble Space Telescope made its millionth science observation on July 4th, using a special instrument called a spectroscope to study the light from a planet a thousand light-years away. The planet is called HAT-P-7b, and HST was looking for signatures of water vapor in the planet’s atmosphere.

It does this by looking at the atmosphere of the planet as it passes in front of its star. The light from the star shines through the gaseous envelope around the planet, and the spectral fingerprints of “stuff” (like water vapor) that is in that atmosphere will show up in the data taken by the spectrometer.

Hubble is quite well-equipped to search out such signatures, and its successor — the James Webb Space Telescope — will be even better able to do such observations. This is the kind of science that HST was built to do — and it’s the kind of science that really grabs my imagination.  It’s really quite cool to think that a telescope orbiting our planet can peer across a thousand light-years of space and spy out the merest whiff of chemical signatures in the atmosphere of another planet.  THAT is what makes this milestone so very, very cool!

You know what else I find very cool?  Back when HST was in severe trouble because of its mirror problems, there were people who felt that we’d wasted our money, that the telescope was a bungle. One of them was Senator Barbara Mikulski of Maryland, now chair of the Senate Commerce, Justice, Science and Related Agencies Appropriations Subcommittee.  She even went so far as to call Hubble a “techno-turkey” and I remember to this day seeing the anger on her face as she did it.  I even quoted her in my book about Hubble (Hubble Vision).

Yet, to her credit, she did step up and champion the cause of repairing the telescope. So, I think it’s cool that we have at least one politician who recognizes the value of science and, as she always points out, the value of inspiring children to become stargazers, scientists, astronauts, and engineering professionals.  I’m glad to see that she is celebrating the millionth observation too — we need many, many more to come.

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By the way, I want to thank the folks at TeachStreet for featuring this blog as one of the Featured Astronomy Blogs. I’ve rambled through their website and they have links to a number really fine writers.

asteroid, astronomy news, Dawn, NASA, planetary science

Dawn at the Asteroid: The Approach

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Vesta Comes into View

A still from a short movie taken as the spacecraft Dawn gets closer to asteroid Vesta. Courtesy NASA/JPL_Caltech/UCLA/MPS/DLR/IDA

Well, this may not look like much, but it’s a big deal in the asteroid-study game. It’s an image of asteroid Vesta, taken with the Dawn spacecraft. If you visit the the mission’s web pages at NASA, you can watch a multi-still “movie” made from frames taken by the spacecraft’s framing cameras on June 1.  The video presents 20 frames, looped five times, that span a 30-minute period. During that time, Vesta rotates about 30 degrees. The images included here are used by navigators to fine-tune Dawn’s trajectory during its approach to Vesta, with arrival expected on July 16, 2011.

Why a mission to Vesta?   It is the only large asteroid with a basaltic surface that formed due to volcanic processes early in the solar system’s history. Asteroids, like comets, are treasure troves of information about what was going 0n in the infant solar system — some 4.5 billion years ago. Here’s how that works. During the earliest history of our solar system, the elements, minerals, and chemical compounds in the solar nebula were distributed throughout the nebula, with their exact locations varying due with their distance from the Sun (and its heat). As distance from the Sun increases, the temperature drops. The young Sun, hot and active, drove away or consumed gases and icy bodies, leaving behind rocky materials to form the inner (so-called “terrestrial” bodies) close by. The icy worlds and gas giants formed farther away.

So, the division of the solar system into terrestrial and gas/ice giant worlds is a large-scale division.  Our planets have changed over time, particularly the Earth, with its atmospheric change, its geological change, and the evolution of life (which has affected conditions on the planet as well). To learn more about the “pure” or what planetary scientists call, the “pristine” materials that made up the big parts of the solar system, we need to look at the smaller-scale objects: asteroids and comets. Studying asteroids (and comets) and studying their compositions are a way of peering into the distant past and learning what it was like, sort of like looking at your baby pictures and seeing what you were then and comparing it to what you are now.

You probably didn’t know this, but Vesta is considered a protoplanet because it is a large body that almost formed into a planet.  It is 330 miles (530 kilometers) across, and is the second most massive object in the Asteroid Belt — that region of space between Mars and Jupiter that is populated with asteroids.  In a few days, we’ll have even better images of this distant “almost-a-planet” world, so keep your eyes peeled for more news.

Speaking of news, this week’s Carnival of Space is up, posted over at John Williams’s Starry Critters web site. Check it out for some unique looks at places and spaces throughout the cosmos.