The two innermost planets, Venus and Mercury, will shine together low in the western sky at sunset on March 10. Here's how to ...

ESA's Solar Orbiter captured views of the planet Mercury passing in front of the Sun. Multiple instruments aboard the ...

Mercury retrograde from March 14 to April 7 travels through Aries and Pisces, coinciding with a full moon and lunar eclipse, ...

"We found that some comets in the inner Oort cloud form a long-lasting spiral structure." Spirals are a repeating theme in ...

Whenever planets are visible in the night sky, they always appear roughly along the same line. This path, known as the ...

Seven planets are on display in the night sky at the end of February, but some will be harder to spot than others. Here’s ...

According to NASA, multi-planet lineups are visible "every few years," but a seven-planet alignment is particularly uncommon, ...

You can add Mercury — the smallest of all the planets ... to Earth to be visible with the naked eye. Because they all orbit in the ecliptic plane, we see them in a magnificent arc across the ...

Saturn, Mercury, Neptune, Venus ... The new definition requires that a planet: orbit the sun is large enough to be round has cleared its orbit of other small bodies. Pluto meets the first ...

Mars, Jupiter and Saturn are frequently seen in the night sky. But because Venus and Mercury orbit closer to the sun than Earth, with smaller, faster orbits, it's more rare for them to make an ...