EarthSky

Look for Cassiopeia and the Big Dipper

Watch the celestial clock and its 2 great big hour hands – Cassiopeia and the Big Dipper – as they swing around the North Star every night!

The left image shows the hydrogen gas density of a simulated dwarf galaxy, viewed from above. The right image shows the same for a real dwarf galaxy, IC 1613. In the simulation, repeated gas inflow and outflow causes the gravitational field strength at the center of the dwarf to fluctuate. The dark matter responds to this by migrating out from the center of the galaxy, an effect known as ‘dark matter heating’.

Dark matter on the move

New evidence suggests that dark matter – the mysterious stuff that makes up a significant percentage of the universe’s mass – can heat up and move around.

More East Antarctica glaciers are waking up

Researchers have said that Totten Glacier, a behemoth with enough ice to raise sea levels by 11 feet (3.4 meters), appears to be melting. Now, they say 4 glaciers west of Totten, and a handful farther east, are also losing ice.

Are December’s solstice and January’s perihelion related?

December solstice 2018 was December 21. Earth was closest to the sun for 2019 on January 2-3. Coincidence?

New Year's Eve fireworks in Singapore 2019.

Why the New Year begins on January 1

Celebrating the New Year on January 1 is a civil event, not an astronomical one. And yet nature cooperates to make January 1 a satisfying time to start anew.

Pluto craft to encounter Ultima Thule

New Horizons is the spacecraft that sent back those amazing images of Pluto in 2015. Ultima Thule is its next target, a billion miles beyond Pluto. The encounter is New Year’s Day, but start watching now!

Why can’t we feel Earth’s spin?

We can’t feel Earth rotating because we’re all moving with it, at the same constant speed.

Eureka! Astronomers find a Big Bang fossil

Only 2 other fossil clouds are known in our universe, and both were serendipitous discoveries. Then astronomers began searching for these rare relics, and found one!

What are your chances for a white Christmas?

For people in the continental United States, here’s your historic probability of getting a white Christmas in 2018.

Tiny droplets of early universe matter created

Researchers have created tiny droplets of the ultra-hot matter that once filled the early universe, forming 3 distinct shapes and sizes: circles, ellipses and triangles

2019 EarthSky Fundraiser

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