Britannica AI Icon
Adding us as a Preferred Source tells Google you trust our content, so our articles show up more often in your Google Search, Discover feed, and AI Overviews.
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites

The Nancy Grace Roman Space Telescope is designed to help astronomers answer questions about dark energy and dark matter, such as how the universe’s expansion has changed over billions of years. Discover how it takes advantage of a cosmic law, the finite speed of light, to peer back in time with its exceptionally wide field of view and reconstruct the universe as it was throughout its history.