Artwork from Jules Verne’s 1865 novel, From the Earth to the MoonLaunching a spacecraft bound for the Moon with the deliberate intention of striking the Moon in a spectacular impact!

Sounds like something out of a Jules Verne novel… but that's exactly what NASA's up to this year with the upcoming LCROSS (Lunar Crater Observation and Sensing Satellite) mission, scheduled for launch on June 2nd and impact sometime in October– exact date TBA.

And it's not unprecedented, either: the Lunar Prospector spacecraft back in 1998/1999, whose instruments detected possible signs of water ice in craters around the Moon's poles, was crashed into the Moon's South Pole at the end of its mission. The aim was to blast up a cloud of material from the lunar surface and spectroscopically analyze the plume in search of water vapor. None was detected then, but that's where LCROSS comes in.

LCROSS will seek to verify the presence or absence of water ice and related hydrated materials buried at the bottom of a permanently shadowed crater floor on the Moon's South Pole. Water ice cannot persist on any part of the Moon's surface that is subjected to sunlight, but because of the Moon's low axial tilt with respect to the ecliptic (the Sun's apparent annual path in the sky)– only about 1.5 degrees– there are craters at the Moon's poles whose floors never see the light of day, all month long and year round. Water ice could persist near the surface in these places.

LCROSS consists of two pieces: a "Shepherding Spacecraft" that will guide the whole affair to the proper location on the Moon's South Pole, and the Centaur rocket stage that propelled the spacecraft to the Moon. The pair will separate, and the Centaur rocket will become the primary impactor, striking ground and producing a crater and plume of ejected material. Viewing the event from above, the Shepherding Spacecraft will use cameras and other instruments to analyze the plume from a distance, and will then follow the same course as the Centaur, descending four minutes after impact through the ejected plume and analyzing material samples as it falls.

Then, the Shepherding Spacecraft, too, will impact the Moon– and the plume it kicks up may well be visible through modest sized telescopes on Earth. We're planning to watch the explosion live through our telescopes at Chabot, weather permitting. Keep an eye on our website for details.

Now, back to Jules Verne for a moment. The launching of a projectile with the intent of striking the Moon was indeed the subject of one of his novels, From the Earth to the Moon, published in 1865. Fired from an enormous cannon, the goal of that post Civil War mission was to catch the attention of anyone living on the Moon, to open up a line of communication with their civilization.

My wife asked me if crashing a probe into the Moon would have any harmful effects, particularly if in fact there is any form of life (subsurface microbes or such) living there. Well, certainly, if you happen to be a lifeform living at ground zero of the impact… but the fact is the Moon is frequently struck by meteorites much larger than the LCROSS impactor anyway. To paraphrase Douglas Adams, "that kind of thing goes on all the time."

One last fun tidbit about the Jules Verne novel: the launch site for his cannon-fired projectile was a place in Florida, 50 miles south of Tampa Bay, and only about 135 miles from the Kennedy Space Center, from which LCROSS will be launched…

Depiction of a major alignment of
the five visible planets in 1059 BCE.

Photo By Ben Burress

There are some pretty good "lineups" coming soon to skies above you.

First of all, "lineups," or alignments, go on in the heavens all the time, though most often they are alignments of objects too faint to easily notice, if at all. With that said, this summer holds some significant alignments of some of the brightest objects in the sky.

First on my hit list is the upcoming Saturn-Mars "near-miss". Though these two planets are not coming physically close to each other (the closest actual distance they come to each other is about 750 million miles), they will align so closely along the same line of sight that on July 11^th they will appear only ¾ of a degree apart-that's not much greater than the width of a Full Moon. The best time to see this pairing is after sunset on the evenings of July 10, 11, and 12, over the western horizon.

The next big ticket alignment is on August 1^st, when the Moon and the Sun occupy the same spot in the sky-the event we call a Total Solar Eclipse. As it happens, we won't be able to see this eclipse directly from the United States, as it will only be visible in Asia. However, NASA will be broadcasting live coverage of the eclipse from Northern China. We'll be showing NASA's broadcast in our planetarium at Chabot Space and Science Center, in case you'd care to come up and enjoy the spectacle. Don't let the fact that the live event goes on around 4:00 AM keep you away…it's worth getting up for!

A bit further out on the calendar is the September alignment of three planets: Venus, Mars, and Mercury. In the dusky twilight of mid-September evenings the three will be gathering. The closest grouping of the trio is on September 11^th, when they will be within about three degrees of each other-close enough that you can just about cover all three with your thumb. Mercury and Mars won't be very bright in the twilight-but Venus, bright enough to spot easily, can help guide your eye to the other two. Using a pair of binoculars will help a lot-but make sure you don't point them that way until after the Sun sets….

In ancient times (and in some cases not so ancient times), different cultures around the world have viewed alignments like these in different ways. Eclipses-both solar and lunar-were regarded by many cultures as bad omens, or bad occurrences (such as the Sun being devoured by a celestial animal-dragon, dog or other-in the case of a solar eclipse).

Planetary alignments were also given special consideration, sometimes being regarded as auspicious (for good or bad-usually the latter). One major alignment of the five visible planets (February 26, 1953 BCE) was believed to have "mandated" the creation of the Hsia Dynasty in China-the first great Chinese Dynasty. (Then, four centuries later, Mars, Mercury, Jupiter and Saturn apparently conspired to bring down that same dynasty-at least, their alignment on December 20, 1576 BCE was interpreted as an indicator of the dynasty's corruption, and it was overthrown by a revolt of believers…).

However you regard the lining up of celestial bodies (astronomically, astrologically, or aesthetically), these alignments are pleasing to watch, and times to reflect upon the constant and cyclic movement among the heavens. Enjoy….