Ask Astro | Page 3 of 23 | Astronomy.com

Solar system planets

Why do the solar system’s planets have different compositions?

Artist's concept of the interior of a white dwarf

Solar System, Stars

After our Sun becomes a white dwarf and cools completely, what will be left?

Comet 67P/Churyumov-Gerasimenko

Does a comet’s period change because it loses mass every time it nears the Sun?

The Carina Nebula, imaged with and without adaptive optics

How does adaptive optics work?

The star Lambda Herculis

Where is the solar system heading?

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?