A new study casts doubt on the universe’s accelerating expansion, suggesting dark energy might be weakening over time.

The European Space Agency's Euclid mission—designed to map the geometry of the dark universe with unprecedented ...

President Trump's 28-point plan for peace in Ukraine would force Kyiv to give up additional territory in the east, cap the ...

Chinese authorities say most of the area of the South China Sea belongs to Beijing, claims contested by a number of other ...

KYIV, Ukraine (AP) — The U.S. and Russia have drawn up a plan aimed at ending the war in Ukraine that calls for major concessions from Kyiv, according to a person familiar with the matter, including ...