"Comet," "star" and "planet" are category names that immediately tell you something important about what they describe.
SPACE.com invites experts in space exploration, science & technology to provide insightful commentary and informed perspective on news, current events, innovations, big ideas and ongoing research. Expert Voices includes Op-Ed analysis and opinion as well as interesting observations from the field and space exploration efforts around the world.
More than 50 years since astronomers first proposed "dark matter," we have no idea what it is and nobody has directly seen it or produced it in the lab.
Ukrainian rocket company Promin Aerospace, which is currently developing an ultralight, autophagic launch vehicle, has conducted a new series of studies on its unique engine.
The discovery of a neutron star emitting unusual radio signals is rewriting our understanding of these unique star systems.
For hundreds of millions of years, Earth’s climate has warmed and cooled with natural fluctuations in the level of carbon dioxide (CO₂) in the atmosphere.
What is it like to be on the surface of Mars or Venus? Or even further afield, such as on Pluto, or Saturn's moon Titan?
Just a few months ago, we were confidently expecting to launch our rover, Rosalind Franklin, to Mars in September as part of the ExoMars mission, a collaboration between Europe and Russia.
Both Voyager 1 and its twin, Voyager 2, carry little pieces of humanity in the form of their Golden Records.
A geologist explains what the "doorway" on Mars really is and why it's so tempting to see recognizable shapes on other worlds.
Setting up any kind of off-Earth mining industry will be no small feat. Let's look at what we're up against.
It sounds like the premise of a bad sci-fi movie: There's some mysterious entity, beyond the boundaries of our galaxy, that is pushing against us with incredible force.
Occasionally, Earth runs through a particularly narrow, dense clump of debris, resulting in a meteor storm.
Nations that don't have their own satellites rely on other countries, and those that want to develop their own satellite infrastructure are running out of options as space fills up.
Mars has almost no oxygen; it's only one-tenth of 1% of the air, not nearly enough for humans to survive.
A racist usage of the Southern Cross contrasts with Indigenous narratives about the constellation, suggesting the symbol can never be contained within a single defining narrative.
The belief of the inevitability of space becoming the next major battlefield runs the risk of becoming a self-fulfilling prophecy.
What goes for moving clocks goes for everything else; physics, chemistry and biology all operate at a slower pace in moving frames of reference.
Particle physics has always proceeded in two ways, of which new particles is one. The other is by making very precise measurements that test the predictions of theories and look for deviations from what is expected.