EarthSky
Thin orange blob stretched across a black background.

Spiral galaxy in profile

Hubble Telescope view of a spiral galaxy – called NGC 3717 – oriented sideways.

Zoom in on the Ghost Nebula

Nebula IC 63 – in the direction of our constellation Cassiopeia – is slowly dissipating under the influence of ionizing ultraviolet radiation from a hot, luminous variable star known as Gamma Cas.

Why leaves change color in fall

The vivid yellows and oranges of autumn leaves are there throughout spring and summer, but hidden.

a big ball, blue around the outside and pink in the middle.

New insights on Venus’ cloud-tops and super-rotation

Why does Venus’ upper atmosphere circle the planet in just 4 Earth-days, while the planet itself takes 243 Earth-days to spin once? Japan’s Akatsuki spacecraft probed the mysterious “super-rotation” of Venus’ clouds.

Graphic showing whereabouts of Akatsuki spacecraft in orbit.

Venus to take center stage in October 2020 observation campaign

Launched in 2018, the BepiColombo mission will have the first of its 2 encounters with Venus – while on its way to Mercury – in October 2020. Coordinated observations at that time will involve 2 spacecraft and multiple ground-based telescopes. 

Learning to live on the moon … underwater

Astronaut teams practice living and working on the moon in the pool at at NASA’s Neutral Buoyancy Lab.

Diagram of w-shaped constellation

Close-up on Cassiopeia the Queen

The constellation Cassiopeia the Queen has the distinct shape of a W or M. Find her in the north-northeast sky on September and October evenings.

Shedding light on black holes

How much of what think you know about black holes is true, and how much is myth? To separate fact from fiction, check out this 4-minute vIdeo from NASA.

Golden ball of Saturn, surrounded by nearly edgewise rings, and a little dot of a moon.

40 years ago today: Pioneer 11 swept past Saturn

Pioneer 11 was the first spacecraft ever to encounter Saturn. A true pioneer, it paved the way for 2 more sophisticated missions – the 2 Voyagers in 1980 and ’81 – and Cassini from 2004 to 2017.

September’s birthstone is the sapphire

Sapphires are typically blue stones, with the color caused by small amounts of titanium and iron in the crystal structure. But if the crystal contains different impurities, you might also see sapphires in gray, yellow, pale pink, orange, green, violet or brown.