Ask Astro | Astronomy.com

Artist's illustration of an asteroid belt around a young star

Robotic Spaceflight, Solar System

How do spacecraft avoid collisions in the asteroid belt?

Image of LEM (Snoopy) on Apollo 10

Human Spaceflight

What happened to the jettisoned Apollo lunar modules?

Composite image of Pluto on several days in 2023

Can you view Pluto in a backyard telescope?

Graph of galaxy rotation showing dark matter's influence

Does dark matter affect our solar system?

Observing, The Moon

How long would it take for an observer using binoculars to notice the Moon’s terminator moving?

Earth's elliptical orbit

How big is Earth’s orbit around the Sun?

The expanding universe

What is the universe expanding into?

emission nebula NGC 7822

Astrophotography

How are long-exposure astrophotos made?

The Blue Snowball Nebula

Deep-Sky Objects, Observing

Will my telescope show color when viewing deep-sky objects?

Cassini image of Saturn

How long will Saturn’s rings last before they disappear?

simulation of merging supermassive black holes

Why weren’t astronomers sure that supermassive black holes could merge?

Lunar eclipse geometry

Science, The Moon

Why can we still see the Moon’s disk during a total lunar eclipse?