A seismic shift occurred in astronomy during the Scientific Revolution, beginning with 16th-century polymath Copernicus and his proposal that the Earth revolved around the sun. By the 17th century, ...

Studying the orbits of thousands of exoplanets shows that large planets tend to have elliptical orbits, while smaller planets tend to have more circular orbits. This split coincides with several other ...

The planets of our solar system move in ellipses. We've known this, so we are told, ever since Johannes Kepler devised his laws of planetary motion in the early 1600s. While it's true that orbits are ...

As planetary systems evolve, gravitational interactions between planets can fling some of them into eccentric elliptical orbits around the host star. Smaller planets should be more susceptible to this ...

It's 2015. You're NASA's chief engineer designing a moonbase for Shackleton Crater at the Moon's south pole. You're also designing a com-system that will allow astronauts constant radio contact with ...

This week's question comes from Wilma David in Ottawa, Ontario. David asks: Given that the sun is almost perfectly spherical (not oblate), why do planets orbit the sun in an ellipse? I understand that ...

How does a planet’s size influence its orbit around its parent star? This is what a recent study published in the Proceedings of the National Academy of Sciences hopes to address as a team of ...

When Johannes Kepler made the intuitive leap in the early 1600s to realize that planetary orbits were not circular, as they had been assumed to be for millennia, he stuck to the trusty ellipse. Indeed ...

This artist concept illustrates how a massive collision of objects perhaps as large as the planet Pluto smashed together to create the dust ring around the nearby star Vega. As planetary systems ...