* Astronomy

Blobrana · L

RE: SMART-1

Blobrana · L

Laboratory simulations of the SMART-1 impact performed at the University of Kent, United Kingdom, suggest that the impact may have caused a clearly elongated lunar crater, and produced a high-speed rebounding for the spacecraft.

This may help explain some properties of the dust cloud observed just after the actual impact of SMART-1 on the Moon.
The simulations were performed by M.J. Burchell and M.J.Cole at the University of Kent. For the test, they used a high-speed, two-stage light gas gun to shoot at 2 kilometres per second a 2-millimitre aluminium sphere that simulated the SMART-1 spacecraft. The target was a tray of sand, similar to lunar soil.

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Blobrana · L

Timing, location, detection of a flash and of ejected material, and a firework generated by the lunar impact of ESA's SMART-1, are the latest results gathered thanks to the ground observation campaign of this historical event.

Blobrana · L

Scientists have received and are analysing the final data gathered by SMART-1 on 2 September, prior to today's Moon impact. This update presents several of the images received, as well as additional images and information from the worldwide ground observation campaign.

The seven AMIE images included in this update article were taken on 2 September by the AMIE camera on board SMART-1 during the last few orbits prior to Moon impact. They were taken between 15:19 - 17:34 CEST (17:19 - 19:34 UT) and were analysed by camera scientists during the night of 2-3 September.
The images include both oblique and nadir (vertical) views, with the camera pointing mode having been selected to best exploit the illumination conditions during the final orbits over the Moon's night side.
In several of the images, the Moon's horizon can clearly been seen; excellent details of the surface are also visible.

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Blobrana · L

Observation of the Impact of Smart-1

A contour map of the flash, so bright that it is saturated, shows that the North (top) and South (bottom) of the flash
are not identical. There is a clear elongation on the South side in the direction of the motion.
The elongations at 45 degrees are due to the diffraction pattern from the secondary mirror supports (the spider).

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At 05h42m21.759s UT, 3 September 2006, a small flash illuminated the surface of the Moon as the European Space Agency's SMART-1 spacecraft impacted onto the lunar soil, in the Lake of Excellence region. The planned impact concluded a successful mission that, in addition to testing innovative space technology, had been conducting a thorough scientific exploration of the Moon for about a year and a half.
The SMART-1 impact took place on the near side of the Moon, in a dark area just near the terminator (the line separating the day side from the night side), at a grazing angle of about one degree and a speed of about 2 kilometres per second. The impact time and location was planned to favour observations of the impact event from telescopes on Earth, and it was achieved by a series of orbit manoeuvres and corrections performed during the course of summer 2006, the last of which was done on 1 September.

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Blobrana · L

RE: SMART-1 Crash

Blobrana · L

RE: SMART-1

Blobrana · L

SMART-1 impact site

Blobrana · L

RE: SMART-1

Blobrana · L

The D-CIXS instrument on ESA's Moon mission SMART-1 has produced the first detection from orbit of calcium on the lunar surface. By doing this, the instrument has taken a step towards answering the old question: did the Moon form from part of the Earth?

Scientists responsible for the D-CIXS instrument on SMART-1 are also announcing that they have detected aluminium, magnesium and silicon.

"We have good maps of iron across the lunar surface. Now we can look forward to making maps of the other elements" - Manuel Grande of the University of Wales, Aberystwyth UK, and D-CIXS' Principal Investigator.

Knowing how to translate the D-CIXS orbital data into ‘ground truth’ has been helped by a cosmic coincidence. On 9 August 1976, the Russian spacecraft Luna 24 was launched. On 18 August it touched down in a region of the Moon known as Mare Crisium and returned a sample of the lunar soil to Earth.
In January 2005, SMART-1 was high above Mare Crisium when a giant explosion took place on the Sun. Scientists often dread these storms because they can damage spacecraft but, for the scientists responsible for D-CIXS, it was just what they needed.
The D-CIXS instrument depends on X-ray emission from the Sun to excite elements on the lunar surface, which then emit X-rays at characteristic wavelengths. D-CIXS collects these X-ray fingerprints and translates them into the abundance of each chemical element found on the surface of the Moon. Grande and his colleagues could relate the D-CIXS Mare Crisium results to the laboratory analysis of the Russian lunar samples.
They found that the calcium detected from orbit was in agreement with that found by Luna 24 on the surface of Mare Crisium. As SMART-1 flew on, it swept D-CIXS over the nearby highland regions. Calcium showed up here too, which was a surprise until the scientists looked at the data from another Russian moon mission, Luna 20. That lander had also found calcium back in the 1970s. This boosted the scientists’ confidence in the D-CIXS results.
Ever since American astronauts brought back samples of moonrock during the Apollo Moon landings of the late 1960s/early 1970s, planetary scientists have been struck by the broad similarity of the moonrocks and the rocks found deep in the Earth, in a region known as the mantle. This boosted the theory that the Moon formed from debris left over after the Earth was struck a glancing blow by a Mars-sized planet.
However, the more scientists looked at the details of the moonrock, the more discrepancies they found between them and the earthrocks. Most importantly, the isotopes found in the moonrocks did not agree with those found on Earth.

"The get-out clause is that the rocks returned by the Apollo missions represent only highly specific areas on the lunar surface and so may not be representative of the lunar surface in its entirety" - Manuel Grande; hence the need for D-CIXS and its data.

By measuring the abundance of several elements across the lunar surface, scientists can better constrain the contribution of material from the young Earth and its possible impactor to condense and form the Moon. Current models suggest that more came from the impactor than from Earth. Models of the Moon’s evolution and interior structure are necessary to translate the surface measurements into the Moon’s bulk composition.
D-CIXS was a small experimental device, only about the size of a toaster. ESA is now collaborating with India to fly an upgraded version on the Indian lunar probe Chandrayaan, due for launch in 2007–2008. It will map the chemistry of the lunar surface, including the other landing sites from where samples have been brought back to Earth. In this way it will show whether the Apollo and Russian landing sites were typical or special.

"From SMART-1 observations of previous landing sites we can compare orbital observations to the ground truth and expand from the local to global views of the Moon" - Bernard Foing, Project Scientist for SMART-1.

Then, perhaps planetary scientists can decide whether the Moon was indeed once part of the Earth.

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