What’s Up This Week? Oct. 25 – 31, 2004

Greetings, fellow sky watchers! As October ends, we have another exciting week in astronomy for you. This week’s highlight is a total eclipse of the Moon! On October 27/28 our “nearest astronomical neighbor” will slide quietly into the Earth’s dark cone of shadow called the umbra, providing most of us from Europe through North America with an inspiring view – but that’s not all. There will also be many other great things to explore this week such as lunar features Tycho, Grimaldi, Langrenus, Mare Crisium and Hercules. We’ll locate the 12th brightest star in the sky and do a “double take” as we learn about Albireo. Rich star cluster, M45 is waiting on you to explore with binoculars, telescopes — or just your eyes and imagination. There’s a little history here and a lot of fun. Now it’s time to mark your calendars…

Because here’s what’s up!

The Virgo Galaxy Cluster is Still Being Formed

At a distance of only 50 million light-years away, the Virgo Cluster is the nearest galaxy cluster to us. It’s a giant structure consisting of hundreds of galaxies, both large and small, spiral and elliptical; 16 objects in this cluster are members of the famous Messier list of space objects. Astronomers have located a large number of planetary nebula floating in the “intercluster” space between galaxies, and theorize that they must be a fraction of the free floating stars and other objects which swarm around the cluster. By measuring the path of these objects, astronomers have been able to track how the Virgo Cluster is still in the process of formation.

Book Review: Sun Observer’s Guide

The Sun Observer’s Guide by Pam Spence is a practical reference for how and why to view our nearest star. Though the uninitiated consider our sun to be a steady source of light and heat, nothing could be further from the truth. Using the proper equipment with appropriate safeguards, viewers can watch a seething tempest. Changes can occur in a few short minutes or, with appropriate record keeping, changes can be seen to vary over decades. This book can start you making worthwhile observations.

Plankton’s Glow Seen from Space

Scientists have figured out how they can use special instruments on board two NASA satellites to detect the early stages of plankton “blooms”. These blooms are caused by excessive runoff of industrial fertilizer which makes marine algae grow – sometimes so thickly that water looks black. Bacteria consume the algae and use up oxygen in the water. This can kill fish in large quantities. The MODIS instruments on NASA’s Terra and Aqua satellites can detect the glow in plankton’s chlorophyll from orbit, and pinpoint exactly where large blooms are forming.

Black Hole at the Heart of a Nebula

Astronomers from the Harvard-Smithsonian Center for Astrophysics have found what they believe is an intermediate sized black hole at the heart of a nebula in a nearby galaxy. Since black holes themselves are invisible, they located it because a spot inside the nebula is emitting a tremendous amount of X-rays, and illuminating a 100 light-year swath. By calculating the amount of X-rays pouring out, astronomers estimate that the black hole has about 25-40 solar masses. It’s unknown how these intermediate-sized black holes form, since so few of them have ever been seen.

Cassini’s First Detailed Look at Titan

NASA’s Cassini spacecraft has delivered some early images of Saturn’s moon Titan; a mysterious world obscured by thick clouds. Some surface features only seen from Earth-based telescopes are now visible to Cassini. The spacecraft used its narrow angle camera’s spectral filters, which are designed to penetrate the thick atmosphere to create the images. Cassini’s first good opportunity to see Titan will be when the spacecraft enters orbit around Saturn in July; it’ll fly past the moon at a distance of only 350,000 km.

New Study Finds Fundamental Force Hasn’t Changed Over Time

In order the represent the Universe mathematically, physicists use a handful of constants, such as the speed of light, or the gravitational constant. One called the “fine structure constant”, or alpha, helps describe how the forces hold atoms together and interact with light. Researchers recently revealed that alpha might have changed over the history of the Universe, but a new study from the European Southern Observatory refutes this evidence. By studying the light from a distant quasar with a high degree of precision, they found that alpha doesn’t seem to have changed over time.

Supernova Explodes Inside a Nebula

Astronomers have measured the light from a supernova, and believe that it was inside a very unusual star system when it exploded. The team used the European Southern Observatory’s Very Large Telescope in Chile to analyze the light from supernova 2002ic, and determined that it was inside a flat, dense, clumpy disk of dust and gas that was previously blown out by a companion star. It seems similar to objects known as protoplanetary nebulae, which are found in our own Milky Way.

Ulysses is Running Out of Power

The NASA/ESA Ulysses spacecraft’s power is starting to run down, and soon it won’t have enough to keep itself warm. When the spacecraft was first launched in 1990 to study the Sun, its reactor produced 285 watts of power, but now almost 14 years later, it’s down to 207 watts. If it gets too much lower, the spacecraft won’t be able to operate the heaters that keep the fuel flowing. Without this fuel, it won’t be able to orient its main antenna towards the Earth to transfer data.

Adaptive Optics Reveal Massive Star Formation

Astronomers at UC Berkeley took advantage of the newly installed adaptive optics system at the Lick Observatory to get clear images of a massive star forming region. The system works by using a laser to create a false star in the sky. A computer tracks the atmospheric turbulence, and warps the telescope’s mirror to compensate. The young massive stars that the team observed are usually too blurry when seen from the ground, so they made the perfect target for the adaptive optics system.