What's Up? The Space Place

Impact!

10/09/09 01:51

NASA's LCROSS mission took this picture of Cabeus Crater just minutes before impacting the shadowed region. (NASA)

By Greg Redfern,
Special to WTOP

With Sir Issac Newton's law of gravity in the driver's seat, NASA's Lunar Crater Observation Sensing Satellite (LCROSS) did a dual death dive into the South Pole of the Moon Friday morning at 7:31 am EDT and 7:35 am EDT. People worldwide, myself included, watched events unfold, including the two impacts, live on NASA TV via the Internet.

The two ton spent upper Centaur stage that had put LCROSS and Lunar Reconnaissance Orbiter (LRO) on their way to the Moon last summer did its final part of the mission. The Centaur's impact into Cabeus Crater was observed by a virtual army of space and ground based telescopes and the Centaur's shepherding spacecraft that slammed into the same crater.

In a press conference held at 10 a.m. EDT and broadcast on NASA TV, NASA released preliminary images that showed the thermal signature and spectroscopic details of the Centaur's impact. The spectra data looked like squiggly lines, but are in fact the chemical fingerprint of the material being observed and the Mother Lode of data. LCROSS scientists were definitive in saying they had acquired a lot of good data that will help them determine whether or not they found the presence of water.

The team was emphatic that it would not state during the press conference whether or not water was found. They did state that the presence of Sodium, a common element, was found in the data. This indicates to them that the Centaur's impact did "stir things up" within Cabeus Crater.

It was hoped that the dual impact would raise an ejecta plume six miles into the lunar sky that could be observed by professional and amateur astronomers. Initial indications are that the plumes were not visible to the eye but sensitive instruments did pick up the thermal (heat) signature of the Centaur's impact. LCROSS instruments also captured a thermal image of the impact crater itself.

Additional processing of all the data from the multiple observing teams, including Hubble Space Telescope (HST), may reveal the plumes' presence. It was clear from the questions and comments from the press corps present that the lack of an easily visible plume was a disappointment.

It will take some time for the LCROSS team, some of whom had been up for over 36 hours, to get all of the data collected, processed and most importantly, analyzed. I can tell you that from what I saw they have lots of interesting and tantalizing tidbits of data to work with. The answer to whether or not the Moon has frozen water deep inside permanently shadowed regions (PSR's) such as Cabeus Crater, lies in the squiggly spectroscopic lines of data.

A big part of this story is that the Moon is back in a big way as a place to explore and learn about. Lunar missions from Europe, China, India and the U.S. in the past several years are rewriting a lot of what we thought about the Moon. LRO is adding to our knowledge of the Moon with every single orbit as it is only 30 miles above the lunar surface and is easily the most sophisticated lunar mission to date.

We already know that very small amounts of water exist in the lunar soil -- this was just announced recently. But if the Moon's poles have significant amounts of frozen water then the Moon becomes very valuable solar system real estate as it means water, oxygen and hydrogen are available to support an outpost.

More as it develops.