In the Sky This Week – July 18, 2017

Eastern Sky – July 18 2017 4:30 AM; Venus orbit is shown in red. Image credit: Stellarium / Bob Trembley

Venus continues to dominate the morning sky in the east, but appears slightly lower in the sky each morning as it pulls ahead of us in its orbit.

Conjunction of the Moon, Venus and Aldebaran – July 19-20, 2017 4:30 AM. Image credit: Stellarium / Bob Trembley

The waning crescent Moon will appear near Venus the the star Aldebaran on the mornings of July 19^th and 20^th. The New Moon will be on the 23^rd.

Southwestern Sky – July 18, 2017 11 PM. Image credit: Stellarium / Bob Trembley

Jupiter and Saturn appear in the south-southwestern sky after sunset; Jupiter will appear slightly lower in the western sky each day as the Earth pulls ahead of Jupiter in its orbit.

Andromeda rising in the northeast – July 18, 2017 11 PM; position of M31 is highlighted. Image credit: Stellarium / Bob Trembley

The constellations Pegasus and Andromeda appear low in the northeast sky after sunset; the wispy cloud of M31, the Andromeda galaxy, makes a good target for telescope observers.

Andromeda Galaxy. Credit: Wikimedia Commons

M31 is the nearest major galaxy to the Milky Way. It is 2.5 million light years distant, and heading straight at us; in a little over 4 billion years, it will collide with the Milky way, and the two galaxies will merge into a large elliptical galaxy.

Don’t expect M31 to look like this time-exposure image in your backyard telescope tho – it typically appears as a circular blue-greenish cloud, surrounded by a larger and dimmer cigar-shaped cloud.

Sharpest ever view of the Andromeda Galaxy. Click to see ZOOMable 6000px image.
Image credit: NASA, ESA, J. Dalcanton (University of Washington, USA), B. F. Williams (University of Washington, USA), L. C. Johnson (University of Washington, USA), the PHAT team, and R. Gendler.

In January of 2015, the Hubble Space Telescope team released this GIANT mosaic image of the Andromeda galaxy. There is a clickable-version that lets you explore a 48,000-light-year-long swath of the Andromeda galaxy in exquisite detail.

The Sky Overhead – July 18, 2017 11 PM. Image credit: Stellarium / Bob Trembley

Animation of the Solar System from July 18-24, 2017. Image credit: NASA Eyes on the Solar System / Bob Trembley

Apps used for this post:

Stellarium: a free open source planetarium app for PC/MAC/Linux.
NASA Eyes on the Solar System: an immersive 3D solar system and space mission app – free for the PC /MAC.