Mercury joins the night sky to complete a seven-planet alignment just after sunset for the end of February. Saturn leaves our view starting in March. Look up!

Stargazers will be treated to a dazzling six- and seven-planet "alignments" in February. A planetary alignment, or a "planet ...

"In about 1604, Johannes Kepler fitted an ellipse model of Mars' orbit to observations of Mars," Bloomer told Space.com. "He came up with the first law of planetary motion that states that planets ...

Although the occurrence climaxed on Jan. 21 with a conjunction—close alignment—of Saturn and Mercury, the planetary parade ...

The planets in our solar system orbit the sun essentially along a line across the sky in a plane called the ecliptic. For that reason, planets in our Earthly sky always appear somewhere along a ...

Someday, in order to pin down its true planetary form, researchers could scour snapshots of the world to look for evidence of a volatile climate from its peculiar orbit and clarify whether it’s ...