May 2000 Sky from the Keeble Observatory
More miscellaneous spaceprobe updates:
Stardust, a probe with a poetic name, has started collecting its own namesake! The probe uses an extremely low-density material called aerogel to collect tiny grains of dust. In February, the probe was commanded to begin collecting dust believed to have been blown into the solar system from the interstellar medium. This phase of collection will last until about May 25th. A second round of dust-gathering is scheduled for 2002. Its primary target is to fly through the tail of Comet Wild-2 in 2004, collecting in a separate aerogel samples of dust blown into space as part of the comet’s tail. Its orbit will return it to Earth, with subsequent recovery of the samples, in 2006. This is another ambitious mission in the Discovery series, part of NASA’s "faster, better, cheaper" model. Hope this one works!
Cassini, the spaceprobe currently bound for Saturn, by way of Jupiter, has also been tasked with some asteroid observations as it traverses that part of the solar system. 2685 Masursky orbits in the inner part of the asteroid belt, a region believed populated primarily by iron-rich bodies. Observations by Cassini suggest that this particular asteroid may not be typical. Images show this object to be nearly spherical, with a diameter of about 20 kilometers. If it were iron and magnesium silicate-rich, as are most of the asteroids at its distance from the Sun, it is too small for gravity to pull it into a spherical shape. Stony asteroids of this size would be somewhat irregular in shape, suggesting that this one may be composed of lighter stuff, perhaps a loose aggregate of small stones or icy material.
As I write, the Shuttle Atlantis is on the pad for another trip to the still unfinished International Space Station. The mission is to boost the orbit and install new batteries to stabilize the station while we wait for the Russian space agency to complete and launch the next module – required before we can send crews for long-term occupancy. Other issues with the station include poor air circulation and extremely noisy conditions. Astronauts will wear special hearing protection while working inside. Meanwhile, MIR is once again the home for a team of Russian cosmonauts. They are supposed to stabilize and evaluate the station as a possible tourist hotel! Stay tuned! In the words of Dave Barry, "I’m not making this up!"
Lunar phases for May: All times are EDT. New Moon on the 4th at 12:12 am; First Quarter on the 10th at 4:00 pm; Full Moon on the 18th at 3:34 am; Last Quarter on the 26th at 7:55 am.
This will again not be a great month for observing planets. Mars is faint and low on the west-northwest horizon at dusk. By midmonth, Mercury will be in roughly the same direction, but brighter. Unfortunately, neither will persist into the evening sky. The Eta Aquarid meteor shower will be relatively easy to observe, since it peaks in the predawn darkness (New Moon!) on the 4th and 5th. As with any meteor shower, your best chance to see anything is to get away from city lights. Find a dark spot with a clear view in the hours after midnight. Small comet fragments hitting the atmosphere (roughly from the northeast) will heat and burn up from friction. These particles are typically the size of a grain of sand, though some larger pieces are occasionally observed.
Castor and Pollux, the two bright stars in Gemini are about all that remain from the winter’s constellations. They remain over the western horizon at about 10:00. Very low to the northwest lies Auriga, with its two brightest stars, Capella and Elnath, probably hard to pull out of the ground clutter and near-horizon haze. Overhead we find the zenith ringed by Ursa Major to the North, and Bootes and Leo to the southeast and southwest, respectively. We also note three bright stars forming a broad triangle to the south: Arcturus, in Bootes to the southeast; Spica, in Virgo, is lower and almost due south; Regulus, in Leo is to the southwest. Arcturus can be found by starting at the "Big Dipper" in Ursa Major, and following the arc of the "handle" towards the southeast. Low to the northeast, we see two bright stars rising – Vega, in Lyra, and Deneb, in Cygnus. Cygnus lies nearly parallel to the horizon, marking as well the plane of our own Galaxy. Indeed, the plane of the Milky Way is nearly coincident with the horizon at 10:00 pm.