Thursday, April 30, 2015
1. See the Eta Aquariid Meteor Shower
The usually reliable Eta Aquarid meteor shower peaks on the night of May 5-6 this year. The shower runs from April 21 – May 20, 2015, with many meteors still visible for several days on either side of the peak. It’s perhaps the best meteor shower of the year for southern hemisphere stargazers, and it’s pretty good for northerners too. The meteors are sandgrain-sized bits left over from Halley’s comet. Like most such showers, the best viewing is just before dawn.
2. Lights Out for Dark Energy?
Astronomers at the University of Arizona announced one of the ‘standard candles’ of the universe, exploding stars called Type Ia supernovae, may not be so standard after all. They found more distant Type Ia supernovae might be intrinsically fainter than more nearby events, suggesting the accelerating expansion of the universe is not as pronounced as once thought. This may mean the effect of the mysterious ‘dark energy’ that causes the expansion is also less important. But that doesn’t disprove the existence of dark energy. As Ethan Siegel explains, there are two more independent observations that show something like dark energy (whatever it may be) still accounts for the majority of the universe.
3. New Images of Pluto and Charon
Yesterday, NASA released rather stirring images from the New Horizon’s spacecraft of Pluto and its Texas-sized moon Charon revolving about their common center of mass. The images also show Pluto rotating about its axis, and large-scale surface features on the former planet’s surface. These are the best images yet captured. The view will only get better as New Horizons gets closer to its brief but historic rendezvous with Pluto just 11 weeks from now.
4. Happy Birthday, Hubble
Well, this makes me feel old, but NASA marked the 25th anniversary of the launch of the Hubble Space Telescope last week. The redoubtable instrument, which began its career with a malformed primary mirror, has revolutionized professional astronomy and helped astronomers to generate more knowledge and understanding of the universe in the past 25 years than in the previous 200 years. Hubble helped refine our understanding of the age of the universe, detect atmospheres on exoplanets, and find millions of galaxies in parts of the sky where no galaxies had been seen before. The New York Times has a brief retrospective video on the launch and legacy of Hubble. And Phil Plait published his favorite “12 1/2” images from Hubble in his column at Slate.
5. Jupiter Through an iPhone
Ottawa-based stargazer Andrew Symes continues to refine his imaging techniques using an iPhone and an 8″ Celestron NexStarSE telescope. An iPhone! The small sensor and pixel sizes of smartphone cameras make them unlikely candidates for astrophotography. But clever developers have created apps that enhance the low-light operation of the iPhone camera. So with a little practice and standard post-processing techniques, Symes has shown it’s possible to take quite acceptable images of Jupiter, Saturn, the Moon, and even brighter deep-sky sights directly at the eyepiece of a telescope with an iPhone.
Wishing you clear skies,
Publisher, Cosmic Pursuits