Precise orbit determination (POD) is vital for satellite navigation, positioning, and timing services, especially as large Low Earth Orbit (LEO) constellations grow in scale. A new method integrates ...

So the bottom line is that the gravity of the closer tidal bulge on the Earth is pulling the Moon forward, which increases ...

A planet's year length depends on its distance from the Sun. Planets closer to the Sun have shorter years. A planet's rotation speed is unrelated to its year length. Planets' orbital speeds vary ...

The Moon appears unchanging in the night sky, but its movement hides a slow transformation. For decades, scientists have observed that our satellite is gradually moving away from Earth, year after ...

NASA’s asteroid impact changed Dimorphos’s orbit, but another strange shift followed. Scientists are still searching for ...

MESSENGER began its 2,000th orbit around Mercury earlier this week, on May 22. The spacecraft completed its primary mission on March 17, 2012, and its first extended mission on March 17, 2013. The ...

High-precision space-based gyroscopes are important in space science research and space engineering applications. In fundamental physics research, they can be used to test the general relativity ...

The winter solstice, famously the shortest day of the year, is nearly three weeks behind us. So why has the sun been rising later than it did on Dec. 21? Like much of our day and night cycles, the ...