Daily Archives: June 16th, 2008

Latest from Phoenix, Super Earths


The Phoenix lander team revealed the latest images from the mission at a press briefing on Friday. This first image shows an area dug by Phoenix’s scoop, which disclosed a bright surface just a few inches down, which may be ice. “There’s still some debate about the bright material,” said Phoenix Principle Investigator Peter Smith. “Not everyone is sure that this is ice. So there’s been some debate on our team, centering around that perhaps there’s a salt layer just under the soil that also would be bright. Everyone does believe there’s ice under the surface, and whether this is ice or not is the question. The other question is, is this thick ice that goes down deep beneath the surface, or is this a thin layer and we’ll be able to scrape through? So being able to scrape with our scoop is a high priority for us.”


This pair of images taken by the Optical Microscope on NASA’s Phoenix Mars Lander offers a side-by-side comparison of an airfall dust sample collected on a substrate exposed during landing (left) and a soil sample scooped up from the surface of the ground beside the lander. In both cases the sample is collected on a silicone substrate, which provides a sticky surface holding sample particles for observation by the microscope.

Similar fine particles at the resolution limit of the microscope are seen in both samples, indicating that the soil has formed from settling of dust.

The microscope took the image on the left during Phoenix’s Sol 9 (June 3, 2008), or the ninth Martian day after landing. It took the image on the right during Sol 17 (June 11, 2008).

The scale bar is 1 millimeter (0.04 inch).


This is the latest color image of Phoenix, its surroundings and the scoop with soil.


While we can’t look inside the Thermal and Evolved Gas Analyzer (TEGA) oven which will “bake” the Martian soil to test the type of gases that are released, we can see that some of the soil has gone into TEGA. “We were finally successful and some of the material has slid down over the screen” said Smith, “sort of like material going over a cheese grater, and some of the material has slid down and filled the oven. We sent the commands for the first operation of TEGA last night, but we don’t have our data back yet, so we can’t report on any results. That will be coming later next week. So this is a very exciting time for us. We find the soil is very clumpy, it’s sticky, it’s an unusual soil not at all like the types of soils we used in our tests, which worked just fine with all the instruments. So we’ve developed another method of collecting samples, which is to tilt the scoop and vibrate it, and so it shakes down a small amount of material onto the instruments.”


And finally, here’s the latest weather report for Mars, on the 17th sol of Phoenix’s stay on Mars.

A commenter joked that Mars and Minnesota have the same temperatures just about. I’m not going to put that to the test because it’s cold enough here in Upstate NY sometimes to put Siberia to shame!

As for ice or salt, it sure looks salty to me. But another commenter pointed out that white salt is from refinement. I guess we have to wait until next week for the oven test results to come out to verify yay, or nay.

Latest Phoenix Images: Ice or Salt?

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Does every single star harbor planets and, if yes, how many?” wonders planet hunter Michel Mayor. “We may not yet know the answer but we are making huge progress towards it.” Mayor and his team of European astronomers have found a star which is orbited by at least three planets. Using the High Accuracy Radial velocity Planet Searcher (HARPS) instrument at the ESO La Silla Observatory, they have found a triple system of super-Earths around the star HD 40307. This is the first system known to have at least three planets.Jupiter or Saturn, and current statistics show that about 1 out of 14 stars harbors this kind of planet.

Back in 1995, Mayor, along with Didier Queloz, made the first discovery of an extrasolar planet around 51 Pegasi, and since then more than 270 exoplanets have been found, mostly around sun-like stars.
Most of these planets are giants, such as

“With the advent of much more precise instruments such as the HARPS spectrograph on ESO’s 3.6-m telescope at La Silla, we can now discover smaller planets, with masses between 2 and 10 times the Earth‘s mass,” says Stéphane Udry, one of Mayor’s colleagues. Such planets are called super-Earths, as they are more massive than the Earth but less massive than Uranus and Neptune (about 15 Earth masses).

HD 40307 is slightly less massive than our Sun, and is located 42 light-years away towards the southern Doradus and Pictor constellations.

“We have made very precise measurements of the velocity of the star HD 40307 over the last five years, which clearly reveal the presence of three planets,” says Mayor

Extra-solar planets are definitely common-place. It’s only going to be a matter of time before we find Earth-type ones. When we do find the first one, the pressure to actually send a probe will be enormous, the technical difficulties will be solved real fast.

For better or worse, the stars are calling us.

Three ‘Super-Earths’ Found Orbiting One Star

Dual hat tips to Universe Today and Centauri Dreams