Deep Impact Probe to Look for Earth-sized Planets

Invisible Pink Unicorn writes "NASA has given University of Maryland scientists the green light to fly the Deep Impact probe to Comet Hartley 2. The spacecraft will pass Earth on New Year's Eve at the beginning of a more than two-and-a-half-year journey to Hartley 2. During the first six months of the journey to Hartley 2, they will use the larger of the two telescopes on Deep Impact to search for Earth-sized planets around five stars selected as likely candidates for such planets. Upon arriving at the comet, Deep Impact will conduct an extended flyby of Hartley 2 using all three of the spacecraft's instruments — two telescopes with digital color cameras and an infrared spectrometer."

Comments

Two is better than one

[Pearson]

I'm glad that they are going to be hitting a couple of birds with the same stone. NASA really needs to get as much bang out of every buck as they can.

I'm frustrated that the pace of space exploration is so slow. There is so much we don't know about our own neighborhood. By now we should have an orbiter around every planet and major moon in this system, and the cost of doing so would be tiny in comparison to the data gathered.

Re:Two is better than one

[Awod]

Ah, but we can't give NASA more than 0.05% of the budget or the terrorists will win, or something like that..

Re:Two is better than one

[Half A Bubble Off Pl]

As long as there is no immediate benefit to the masses from space exploration (or science in general) it will always be playing second or third fiddle to "glamor" policies like war and social programs.

What looks better on the tube --- enemies getting their asses kicked and old people looking neglected or the 1 minute orgasmic thrill of a rocket booster launch. Like a firework, a quick flame and WHOOSH, gone from view. Who cares about data collection and knowledge increases --- much too cerebral for Joe Blow voter. Whereas blown up "enemy installations" and insurgent body counts make for much better evening news updates. Throw in a few vacant-eyed old people scrapping by on SS only and you have yourself NEWS AT 11 everyday.

So sad, but almost inevitable, given attention spans of the masses, it's "What They Want" after all ...

Re:Two is better than one

[Xzzy]

After the budget the Senate passed on Monday, doing much of anything is pretty unlikely.

NASA were just about the only guys to get a budget increase (3%), and even what they got will require sacrificing programs.

Landscape is even worse for other fields of science:

http://sciencenow.sciencemag.org/cgi/content/full/2007/1218/1

Probe trajectory?

[skoaldipper]

The total trip -- measured from its December 31, 2007 flyby of Earth to its closest encounter with the comet on October 11, 2010 -- will be roughly 1.6 billion miles or some 18 times the distance from the Earth to the sun. It will take the spacecraft three trips around the sun before it can intercept the comet, which at that time will be at a distance of some 12.4 million miles from Earth.

3 slingshot trips. Ok.

At the nearest point of its flyby of Hartley 2, the spacecraft will be some 550 miles from the comet.

Sweet. A close shave.

What I couldn't decipher is how long will the probe be in close proximity to the comet? On opposing vectors? Or will the slingshot put it alongside the same trajectory as the comet coming up from behind? If the latter, now that's a pretty cool set of calculations, and should make for a nice long study of the comet.

Re:how big

[edunbar93]

It doesn't need to be very big. Even ground-based amateur astronomers are able to detect transiting exoplanets using consumer-grade imaging equipment. You basically need a CMOS camera that's sensitive enough, and know when and where to look. If you record the star's brightness over the expected period of time, you can see the difference in your own measurements.

The drawback of using Hubble to do this is that astronomers the world over are competing for time on it, so it's booked solid. The University of British Columbia has a satellite of its own, with a 150mm telescope (much smaller than Hubble's 2m) in orbit specifically to look for transiting extrasolar planets. They basically observe one star for months at a time, hoping to catch the dip in the star's brightness that would mean a planet is transiting. The telescope on this probe is probably about the same size, and since it's not going to be doing anything for the next year or so, why not point it at some candidate stars for that period? You might just get lucky. The fact that there's no atmospheric interference is really what makes the difference between discovering a jupiter-sized planet and an earth-sized planet with this method.

Details on the instruments

[Midnight Warrior]

For those of you who miss it on the main web-site, Ball Aerospace developed most of the scientific instruments. They are becoming pivotal to many of today's space-based observation instruments. Details on their involvement with Deep Impact are here.