How to see the partial lunar eclipse in the autumn night sky

The Moon.

The Moon. - Credit: Ariella Emmett

What’s in the sky next month?

Next month we have a partial lunar eclipse! The lunar eclipse will take place on November 19. Lunar eclipses occur when the Earth is in a direct line between the sun and the Moon. The Earth’s shadow falls across what would usually be a full moon, giving the Moon a reddish hue.

So why does the Moon appear red during an eclipse? Light from the sun hits the Earth’s atmosphere and is refracted, or bent, so that it still hits the moon. Blue light gets scattered away, so only reddish light makes it to the surface. This is the same reason sunsets are red!

We can only see a part of this month’s eclipse as the Moon sets before we can see the full shadow. The partial eclipse starts at 6 am on November 19, and lasts until 7:24, so you only have a short window to see it. You’ll have to wait until May 16th to catch the next lunar eclipse!

As the nights get longer, this month is a great time to get started with backyard astronomy. An eclipse is spectacular to view through a telescope, binoculars, or even just your eyes!

Moon Alpine Rille.

Moon Alpine Rille. - Credit: Steve Heliczer

Astronomy at the University of Hertfordshire

What is an Extended Green Object (EGO) and is it aliens? Despite the strange name, EGO’s are not aliens, nor are they green at all! They are clouds of gas that show up when we study the sky at particular wavelengths. So why do we call them green?

Historically, the Spitzer Space Telescope, which discovered EGOs, would take images of the sky with three different filters to see how the sky changed depending on which filter was used. They assigned colors to each filter, to better highlight which light came from which filter. The color green was assigned to the 4.5 micrometer filter. When they created their images, they found numerous extended green blobs!

Why are these objects so interesting? EGOs are often associated with young star formation. One particular EGO, G19.01–0.03, was observed by Dr. Gwen Williams and her collaborators. The team used the ALMA telescope array to investigate the EGO in high detail. They were looking for evidence of proto-stars and their formation.

They found a disk of material spiraling around the proto-star, feeding the star's growth. When they added up all of the material in the disk and the proto-star itself, they found G19.01–0.03 to be 40-70 times more massive than our sun!

Spitzer color image of G19.01–0.03 with data from several studies marked. Provided by Williams, G et al 2021

Spitzer color image of G19.01–0.03 with data from several studies marked. Provided by Williams, G et al 2021 - Credit: Williams, G et al

That makes G19.01–0.03 possibly one of the largest proto-stars discovered. They also found evidence that there may be a second star forming, though additional observations are needed to confirm this. This kind of study is exciting, as it helps astronomers understand the conditions under which stars form.

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Latest astronomy news from around the world

Why are astronomers so excited about taking a picture of a dog bone? Because it’s in space! Kleopatra is a very peculiar object in the asteroid belt between Mars and Jupiter. Discovered 20 years ago using radar, astronomers noted its unusual shape, two spheroids attached by a thin region in the middle, much like a dog bone.

When a planet like the Earth forms, it is massive enough that its gravity forms it into a sphere. Asteroids like Kleopatra do not have enough mass to guarantee they end up as a globe. This means we get all sorts of unusual shapes.

To get a better picture of the asteroid, astronomers at the SETI institute in the USA and Laboratoire d'Astrophysique de Marseille in France used European Southern Observatory's Very Large Telescope (VLT) to view Kleopatra as it spun.

Over time, they were able to build a detailed 3-D map of the asteroid. They hope to use their map of Kleopatra to better understand how asteroids formed during the early years of the solar system.

Astronomy picture of the month

Photographed by Steve Heliczer from his back garden.

The Andromeda Galaxy pictured by Steve Heliczer.

The Andromeda Galaxy. - Credit: Steve Heliczer

The Andromeda Galaxy, M31 and originally the Andromeda Nebula, is a barred spiral galaxy approximately 2.5 million light-years from Earth and the nearest large galaxy to the Milky Way. It is estimated to contain 1,000 billion stars.

The galaxy's name stems from the area of Earth's sky in which it appears, the constellation of Andromeda. The Andromeda Galaxy has a diameter of about 220,000 ly, making it the largest member of the Local Group in terms of extension.

The number of stars contained in the Andromeda Galaxy is estimated at one trillion or roughly twice the number estimated for the Milky Way.

The Milky Way and Andromeda galaxies are expected to collide in around 4-5 billion years, merging to form a giant elliptical galaxy.

With an apparent magnitude of 3.4, the Andromeda Galaxy is among the brightest of the Messier objects, making it visible to the naked eye from Earth on moonless nights