Stars in the Sky

Planet Neptune Facts

Neptune is not visible to the unaided eye and is the only planet in the Solar System found by mathematical prediction rather than by empirical observation. Unexpected changes in the orbit of Uranus led Alexis Bouvard to deduce that its orbit was subject to gravitational perturbation by an unknown planet. The position of Neptune wasRead more

Stars in the Sky

Mercury Planet Size

Mercury’s axis has the smallest tilt of any of the Solar System’s planets (about ​1⁄30 degree). Its orbital eccentricity is the largest of all known planets in the Solar System;[b] at perihelion, Mercury’s distance from the Sun is only about two-thirds (or 66%) of its distance at aphelion. Mercury’s surface appears heavily cratered and isRead more

Stars in the Sky

Kepler Telescope NASA

Designed to survey a portion of Earth’s region of the Milky Way to discover Earth-size exoplanets in or near habitable zones and estimate how many of the billions of stars in the Milky Way have such planets, Kepler’s sole scientific instrument is a photometer that continually monitored the brightness of approximately 150,000 main sequence starsRead more

Stars in the Sky

International Space Station Orbit Speed

The first ISS component was launched in 1998, with the first long-term residents arriving on 2 November 2000. Since then, the station has been continuously occupied for 19 years and 70 days. This is the longest continuous human presence in low Earth orbit, having surpassed the previous record of 9 years and 357 days held by Mir. The latestRead more