Moon Impact by LCROSS – a historical event

The final countdown begins for LCROSS spacecraft to impact the Moon on Friday, October 9, this will be a once in a life time opportunity to witness the event.

Based on the projections, scientists predict there should a visible ejecta cloud rising 6km above the lunar surface. NASA/Ames scientist Brain Day says, that it’s possible to view this impact with a 10inches or larger telescope. Many amateur astronomers and some ground based telescopes are already geared up to photograph and video the event.

Few hours from now a 2270kg (5000pounds) Centaur will slam into Cabeus crater, making an impact at a speed of 9000kmph (5600mph) creating a crater roughly about 60 or 70 feet wide, and 16 feet deep. This impact will eject roughly 385tons of lunar dust and soil. This impact will be followed by Sherpherding spacecraft which is also expected to slam into moon surface. Both spacecrafts will send data back to Earth through out the process, and scientist hope to see signs of lunar water.

Impact location

When: As a result of the latest TCM (Trajectory Correction Maneuvers), the time of impact on Friday, October 9, 2009:

--Centaur impact time: 11:31:19 UTC, 7:31:19 EDT, 4:31:19 PDT
--Shepherding spacecraft impact time: 11:35:45 UTC, 7:35:45 EDT, 4:35:45.

Note that the impact time may be changed as the event comes closer. Go to NASA LCROSS site for the up-to-date time changes.

Where: Both spacecraft are targeting Cabeus crater. The impact site coordinates are -84.675, 311.275 E.

Cabeus crater is located about 100 km from the south pole of the Moon.

You can download Targeting Coordinates, Timing, and Finder Charts at:

How to witness the event:
Many space/astronomy societies, planetariums, institutions, museums, amateur astronomers around the world will gather to hold events to witness the event.

List of events can be seen at

Thousands around the world will watching it live via web tv.


LCROSS background info

The LCROSS mission is a search for water on the moon. The LCROSS mission is going to do this by sending a rocket crashing into the moon causing a big impact and creating a crater, throwing tons of debris and potentially water ice and vapor above the lunar surface. This impact will release materials from the lunar surface that will be analyzed for the presence of hydrated minerals which would tell researchers if water is there or not. The two main components of the LCROSS mission are the Shepherding Spacecraft (S-S/C) and the Centaur upper stage rocket. The Shepherding Spacecraft guides the rocket to a site selected on the moon that has a high probability of containing water. Because they have only one chance with this mission in finding water, the researchers have to be very precise where they program the Shepherding Spacecraft to guide the rocket.
The launch

The Shepherding Spacecraft and Centaur rocket are launched together with another spacecraft called the Lunar Reconnaissance Orbiter (LRO). All three are connected to each other for launch, but then the LRO separates one hour after launch. The Shepherding Spacecraft guides the Centaur rocket through multiple Earth orbits, each taking about 38 days. The rocket then separates from the Shepherding Spacecraft and impacts the Moon at more than twice the speed of a bullet, causing an impact that results in a big plume or cloud of lunar debris, and possibly water. While this is happening the Shepherding Spacecraft, which has scientific instruments on-board including cameras, is taking pictures of the rocket’s descent and impact into the moon. Four minutes later, the Shepherding Spacecraft follows almost the exact same path as the rocket, descending down through the big plume and analyzing it with special instruments. The analysis is specifically looking for water (ice and vapor), hydrocarbons and hydrated materials. The Shepherding Spacecraft is collecting data continuously and transmitting it back to Earth before its own demise. This crash will be so big that we on Earth may be able to view the resulting plume of material it ejects with a good amateur telescope.

Names on the LRO


As a part of the shared Lunar Precursor Robotic Program – the first American mission to the Moon in over ten years – LCROSS was launched together with the Lunar Reconnaissance Orbiter.

The Lunar Reconnaissance Orbiter (LRO) is currently (as of October 2009) orbiting the Moon on a low 50 km polar mapping orbit. The LRO mission is a precursor to future manned missions to the moon by NASA. To this end a detailed mapping program will identify safe landing sites, locate potential resources on the moon, characterize the radiation environment, and demonstrate new technology.
Engineers are shown here with the microchip

In response to LRO's "Send Your Name to the Moon" initiative, the spacecraft carries a microchip with nearly 1.6 million names submitted by the public. The microchip encased in a radiation hardened container and attached to the back of the propulsion module access panel.

I included my name as well :)

Thilina Heenatigala
General Secretary
Sri Lanka Astronomical Association

Source: NASA, Wiki, Universe Today
Image Credits: NASA, GSFC, AMES, Thilin Heenatigala