Archive for the ‘LRO’ category

AGU 2009 – Day 2

December 17, 2009

I started off day 2 of AGU at a couple of lunar talks showing off data from the Lunar Reconnaissance Orbiter. Unfortunately, I missed the early sessions about the high-res cameras, but the bright side was that I learned abount some instruments I was less familiar with. First was the Lunar Orbital Laser Altimeter – LOLA. A similar instrument on Mars Global Surveyor, MOLA, revolutionized our view of Mars. The MOLA map has become the standard to which all other mars maps are registered, and LOLA is going to do even better for the moon. LOLA works by sending five laser pulses in a pattern similar to the spots on the “five” side of a die. The spacecraft then recieves the reflected laser light and determines the distance to the surface, and therefore the topography. The advantage of having five spots is that it also gives astoundingly good measurements of the slopes.

Credit: NASA/LOLA team

After the LOLA talks, I heard about the results from the cosmic ray detector, CRaTER, on LRO. Apparently right now is a good time to observe cosmic rays because the sun is not very active. The current weak solar wind pressure allows more cosmic rays into the inner solar system! Understanding the radiation environment is important for sending hardware and people to the moon. One significant result that the CRaTER team reported was that even though the moon blocks cosmic rays as you get close to it, the total radiation increases because rays that hit the surface send up showers of secondary radiation. There is also no evidence that the amount of radiation on the moon decreases when Earth’s magnetosphere tail points toward the moon, as some people had suggested.

An animation of a cosmic ray hitting Earth's upper atmosphere. A similar shower of secondary particles is produced when cosmic rays hit the moon. Image creadit: U. Chicago

After that, I headed over to listen to Mars talks. Serina Diniega gave a nice presentation about her discovery of active gullies forming on dunes in the southern hemisphere. She showed evidence of several dune gullies for which there are “before and after” images showing noticeable changes. Serina suggested that frost accumulating in the upper alcoves of the gullies could trigger the changes, which would be consistent with the observation that most changes happened in southern winter. A related talk by Colin Dundas showed similar results, with HiRISE observations revealing fresh gullies on pole-facing slopes in the southern hemisphere.

An example of a fresh gully deposit in HiRISE image PSP_002200_1380.

After a few more Mars talks, I headed back to the moon to hear about LCROSS. I caught the tail end of a talk about the Lyman-alpha Mapping Project (LAMP) on LRO. This instrument uses the light emitted by hydrogen in stars to illuminate the dark craters on the moon, which is a really cool idea. Interestingly, the permanently shadowed craters look “dark”, implying that they contain something (ice) that absorbs UV light. LAMP also saw the plume kicked up by the LCROSS impact, and detected hydrogen emission, as well as, oddly enough, mercury (Hg) emission. Apparently, Mercury is volatile enough that over geologic time it also gets concentrated in shadowed craters. Future astronauts drinking the moon’s water will have to watch out for mercury poisoning!

Tony Calprete gave a nice overview of the LCROSS mission. He explained that the reason the plume wasn’t visible from earth was because they ended up selecting a crater that was known to have hydrogen, since LRO was going to be positioned to get good observations from orbit. He showed some of the spectra recorded by various instruments, which had evidence for all sorts of good stuff, including H2O, CO2, methane (CH4), SO2, ammonia (NH3), H2S, and even a couple of mystery lines that some people on the team think might be gold! (There’s gold in them thar hills?)

A second LCROSS talk by Peter Schulz focused on the cratering process. The most interesting aspect was the effect of a hollow projectile (such as the big empty centaur rocket used as the LCROSS impactor) on the plume behavior. It turns out a hollow projectile causes the crater ejecta to form a higher plume that spreads out less. He also pointed out that the reason the LCROSS impact did not look like the Deep Impact plume was because deep impact was a very high speed impact into a low-gravity object with a solid projectile, while LCROSS was a slow hollow impactor hitting a body with significant gravity.

Stay tuned for the Day 3 post, which will include some particularly interesting sessions about Venus and astrobiology and society!

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LCROSS preliminary results

November 5, 2009

Hey remember when we bombed the moon? Here’s an interesting article about some preliminary results from LCROSS. I was especially surprised when they said that there may be mercury at the impact site. They say they’re seeing spectral lines that could be produced by iron, magnesium or mercury, but then the article goes on as if mercury is the likeliest candidate! I’m skeptical. Fe and Mg are common in lunar rocks. Mercury: not so much. Oh well, it’s an interesting update anyway, and it sounds like the real juicy results are still in the works.

PS – Have you voted today for my MSL: Mars Action Hero article over at the scientificblogging.com science writing competition? Remember, you can vote daily!

New Photos of Stuff on Other Worlds

October 29, 2009

I always make the mistake when on vacation of taking too many pictures of scenery and not enough pictures of people. Years down the road, the most interesting photos are not landscapes, but the ones that we can look at and say “I remember when we did that!”. And that’s why I think it’s great that we now have cameras around the Moon and Mars that can do the same. LROC at the moon has been able to take some spectacular photos of the Apollo landing sites, including a new one shown below. HiRISE at Mars has been able to take photos of the Mars rovers, Viking landers, and more recently the Phoenix lander.

Phoenix went silent as northern Martian winter crept in, covering it with CO2 frost, but the latest HiRISE image, taken in the spring, shows an ice-free Phoenix! It probably won’t wake up again, but it’s good to see our lander again. The spring images are somewhat grainy because the sun had just peeked above the horizon and light levels were very low. Emily Lakdawalla has a post with more information about this and other HiRISE images of Phoenix.

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Credit: NASA / JPL / UA / animation by Emily Lakdawalla

If it’s fun to see our robots again, it’s even cooler to see evidence of humans landing on the moon. Now that LRO is in its final orbit around the moon, it is returning some really excellent photos of the Apollo landing sites, including this new one of the Apollo 17 site. You can even see the flag! For more information and closer views, check out the LROC site.

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This high-resolution view of the Apollo 17 landing site shows details as small as the flag! Click to go to the LROC site for higher-resolution versions.

To the Moon! Zoom, Bang!

October 7, 2009

633px-LCROSS_Centaur_1

As I write this, there is a NASA spacecraft on an unstoppable collision course with the moon.

Early on Friday morning it will impact a crater near the moon’s south pole at 9000 km/hr, causing an explosion that will excavate 350 tons of lunar rocks, blasting them up into space and leaving a 66 foot-wide crater.

Of course, this is all intentional. The LCROSS mission will use the upper stage of the rocket that launched the Lunar Reconnaissance Orbiter to the moon as a missile to blast the possibly ice-bearing crater Cabeus in much the same way that the Deep Impact mission blasted a hole in comet 9P/Temple. The hope is that the ejecta from the LCROSS impact will reveal that the crater does indeed contain ice.

In addition to the “shepherd” spacecraft that will follow the big Centaur stage to its explosive death, snapping pictures all the while, scientists all over the world will be watching the moon with their own telescopes. In fact, even large (12 in or 30 cm) amateur telescopes may be able to see the impact!

Even if you don’t have a big telescope to peer through, NASA TV will be covering the impact. The impact is planned to occur on Oct 9, 2009 at 11:31:30 UTC (04:31:30 am PDT), and NASA TV coverage will begin at 10:15 UTC (03:15 am PDT).

Stay tuned! It promises to be a blast! (Sorry, the pun had to be made.)

LRO Images of Apollo Landing Sites!

July 17, 2009

Just in time for the 40th anniversary of Apollo 11, the Lunar Reconnaissance Orbiter Camera (LROC) team have released images of the Apollo landing sites. These pictures show the lower half of the Lunar Module (LM), the scientific instruments left on the surface, and even the tracks where the astronauts walked! Awesome. Of course, the moon hoax believers will not be convinced by this photographic evidence that humans have walked on the face of the moon, but for the rest of us, these pictures are awesome! And LRO isn’t in it’s primary orbit yet! Eventually he’ll have pictures with twice this resolution.

See more images and learn more about them at the NASA press release. And Bad Astronomy has a rather enthusiastic post about them too.

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Lunar Reconnaissance Orbiter: at the Moon and Returning Data!

July 4, 2009
One of the first images of the lunar surface from LROC. The camera has a high enough resolution to see the equipment left at the Apollo landing sites, and those are some of the top priority targets once LRO reaches its primary mission orbit.

One of the first images of the lunar surface from LROC. The camera has a high enough resolution to see the equipment left at the Apollo landing sites, and those are some of the top priority targets once LRO reaches its primary mission orbit.

I was completely delinquent about reporting this due to the craziness that was my June, but the Lunar Reconnaissance Orbiter launched on June 18 and has arrived at the moon and is already returning data. As a Mars scientist that is amazing to me. If it were a Mars probe, there would be ~7 months between launch and orbital insertion, but with the moon, it only takes a few days. Last I heard they are still refining the orbit, but the pictures from LROC, the high resolution camera (similar to the HiRISE camera orbiting Mars) are spectacular, and they will only get better. And remember, since LRO is at the moon rather than at Mars, it is going to be blasting data back to earth through a firehose rather than a straw. Many hundreds of gigabits per day! I think this mission is going to do a lot to bring the Moon back into the spotlight.