EarthSky - Earth, Space, Human World, Tonight

Famous Comet 67P/C-G will be closest until 2214

September 24, 2021

September deep sky: Cygnus Loop and Bode’s Galaxy

EarthSky readers shared two amazing September deep sky photographs with us: the Cygnus Loop, a nebula that stretches into Vulpecula, and Bode's Galaxy, aka M81.

Kelly Kizer Whitt

September 24, 2021

Space

Martian super volcanoes lasted millions of years

NASA scientists say that there were once thousands of volcanic eruptions on Mars. These explosive blasts, in the northern Arabia Terra region, were "super eruptions," the largest and most powerful kind known. The intense activity continued for about 500 million years, about four billion years ago.

Paul Scott Anderson

September 24, 2021

Brightest Stars

Delta Cephei helps measure cosmic distances

Delta Cephei is an inconspicuous variable star in the northern constellation Cepheus the King. This star helps establish the cosmic distance scale.

Bruce McClure

Shireen Gonzaga

September 24, 2021

Space

Auroral tails for Jupiter’s moons

The Juno spacecraft observed footprint tails of aurora on Jupiter’s atmosphere. Three of Jupiter’s closest large moons create these auroral tails.

Kelly Kizer Whitt

September 23, 2021

Human World

Space

Futuristic space concrete uses astronauts’ blood

Scientists in the U.K. have developed a kind of "space concrete" using dust and human blood that could be used for future human habitats on Mars or the moon.

Paul Scott Anderson

September 23, 2021

Human World

Pablo Neruda, a poet who embraced cosmic beauty

Pablo Neruda was a famous Chilean poet who wrote: "Every day you play with the light of the universe." Neruda died on this date, September 23, in 1973.

Deborah Byrd

September 23, 2021

Astronomy Essentials

Equinox sun is over Earth’s equator

The equinox is September 22. From around the world on the day of an equinox, the equinox sun pretty much rises and sets due east and west.

Deborah Byrd

September 22, 2021

Human World

Bible story of Sodom revisited. Was it a meteor strike?

The Bible story of Sodom and Gomorrah describes ancient cities destroyed for their wickedness. New research suggests a meteor impact instead.

EarthSky Voices

September 22, 2021

Brightest Stars

Gamma Cephei, aka Errai, a future North Star

Gamma Cephei - or Errai - is a binary star system that will someday be Earth’s North Star. Gamma Cephei is home to the first exoplanet ever discovered.

September 22, 2021