An image of Betelgeuse taken at sub-millimeter wavelengths taken by the Atacama Large Millimeter/submillimeter Array (ALMA).

How far is Betelgeuse?

Recent speculation that Betelgeuse might be on the verge of going supernova prompted many to ask: how far away is it? But getting a distance measurement for this star has been no easy task.

What’s a penumbral eclipse of the moon?

During a penumbral eclipse, very observant people in the right spot on Earth will look up and notice a dark shading on the moon’s face. Others will look and notice nothing at all.

A totally eclipsed sun with a bright light emerging on one side: the diamond ring effect.

What is an eclipse season?

A solar eclipse can happen only at new moon. A lunar eclipse can happen only at full moon. Additionally – for an eclipse to occur – the new moon or full moon has to take place within an eclipse season.

Lengths of lunar months in 2020

The longest lunar month in 2020 starts with the new moon on February 23, and concludes with the new moon on March 24. Its duration will be 29 days 17 hours and 56 minutes.

Top 10 tips for meteor-watchers

How to watch a meteor shower. Tips for beginners.

Amazing photo of a meteor streaking right in front of Venus

EarthSky’s 2020 meteor shower guide

All you need to know about major meteor showers in 2020.

Dark skies for 2020’s Quadrantid meteors

2020’s first major meteor shower is the Quadrantid shower. Best time to watch is probably late night January 3 until dawn January 4. Northerly latitudes are favored. No moon in the predawn hours (2 a.m. until dawn) this year!

January 2020 guide to the bright planets

In January 2020, dazzling Venus lights up the early evening sky. Moderately-bright red Mars comes up before dawn. Late in the month, you might catch elusive Mercury at dusk and giant Jupiter at dawn. Ringed Saturn hides in the sun’s glare all month.

Close and far moons of 2020

The moon will swing to its farthest from Earth for 2020 on March 24, and then comes closest to Earth about 2 weeks later, on April 7.

Sun in zodiac constellations, 2020

The sun in our sky moved in front of the constellation Sagittarius on December 18, 2019. It’ll move in front of the constellation Capricornus on January 20. Click here for sun-entry dates to zodiac constellations in 2020, using boundaries for constellations set by the International Astronomical Union in the 1930s.

Star Sirius rings in New Year!

Dog Star Sirius reaches its highest point in the sky around midnight every New Year’s Eve. For this reason, it might also be called the New Year’s star.

Middle of eclipse season December 30

The annular solar eclipse on December 26, 2019, happened some 4 days before the middle of the eclipse season, which came to pass on December 30, 2019.

Thin partial eclipse with a woman and child standing on a hillside, pointing at it.

Photos of December 26 ‘ring of fire’ eclipse

The December 26, 2019, annular or ‘ring of fire’ solar eclipse was viewed across a narrow track that started at sunrise in Saudi Arabia and ended at sunset over the North Pacific Ocean.

Was the Christmas Star real?

Are there any possible astronomical explanations for the Star of Bethlehem or Christmas star?

Mirfak is Perseus’ brightest star

Mirfak isn’t as famous as Algol, its brother star in the constellation Perseus. But Mirfak is easier to find and can help guide you to Algol.

Solstice tale of two cities

December solstice sunrise comes at the same time for St. Augustine, Florida, and New York City. But St. Augustine has an hour more of daylight than New York. Here’s why.

December solstice: All you need to know

It’s getting closer. December solstice 2019 arrives on December 22 at 04:19 UTC. That’s December 21 for much of North America. High summer for the Southern Hemisphere. For the Northern Hemisphere, the return of more sunlight!

How often are there 3 eclipses in a month?

In a calendar month, 3 eclipses are rare. But in a lunar month, 3 eclipses are more common. From 2000-2050, it happens 14 times.

A line of white dots, with a grid system laid over it. A faint, fuzzy line connects some of the dots.

Astronomers spy the Geminid meteors’ dust trail in space

Astronomers held a press conference this week to discuss the trail of dust left by 3200 Phaethon – the mysterious blue rock-comet that spawns the Geminid meteor shower each year. This object was one of the 1st to blur the distinction between asteroids and comets.

This weekend’s Geminid meteor shower

The Geminid meteor shower – one of the highlights of the stargazing year – will peak on the mornings of December 13, 14, and 15, 2019, though under the light of a bright moon. The Geminids are bright, too. You still might see some!