The Extraordinary Spiral in LL Pegasi

2021-11-29 Jonathan Lodge

What created the strange spiral structure on the upper left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected. The huge spiral spans about ...

A High Cliff on Comet...

2021-11-28

This high cliff occurs not on a planet, not on a moon, but on a comet. It was discovered to be part of the dark nucleus of Comet Churyumov-Gerasimenko (CG) by Rosetta, a robotic spacecraft launched by ESA that rendezvoused with the Sun-orbiting ...

Messier 101

2021-11-27

Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way. M101 was ...

Great Refractor and Lunar Eclipse

2021-11-26 Laurie Hatch

Rain clouds passed and the dome of the Lick Observatory's 36 inch Great Refractor opened on November 19. The historic telescope was pointed toward a partially eclipsed Moon. Illuminated by dim red lighting to preserve an astronomer's night ...

At the Shadow's Edge

2021-11-25 Jean-Francois Gout

Shaped like a cone tapering into space, the Earth's dark central shadow or umbra has a circular cross-section. It's wider than the Moon at the distance of the Moon's orbit though. But during the lunar eclipse of November 18/19, part of the Moon ...

Pleiades: The Seven Sisters Star Cluster

2021-11-24 Damien Cannane

Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as large and clear as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen without binoculars from even ...

The Sun in X-rays from NuSTAR

2021-11-23

Why are the regions above sunspots so hot? Sunspots themselves are a bit cooler than the surrounding solar surface because the magnetic fields that create them reduce convective heating. It is therefore unusual that regions overhead -- even much ...

Lunar Eclipse over a Skyscraper

2021-11-22 Yuri BeletskyCarnegieLas Campanas ObservatoryTWAN

Why is the Moon on top of this building? Planning. It took the astrophotographer careful planning -- including figuring out exactly where to place the camera and exactly when to take the shot -- to create this striking superposition. The single ...

Introducing Comet Leonard

2021-11-21 Dan Bartlett

Here comes Comet Leonard. Comet C/2021 A1 (Leonard) was discovered as a faint smudge in January 2021 when it was out past Mars -- but its orbit will take the giant shedding ice-ball into the inner Solar System, passing near both Earth and Venus ...

An Almost Total Lunar Eclipse

2021-11-20 Robert Fedez

Predawn hours of November 19 found the Moon in partly cloudy skies over Cancun, Mexico. Captured in this telephoto snapshot, the lunar disk is not quite entirely immersed in Earth's dark umbral shadow during a long partial lunar eclipse. The ...