The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

All of our solar system’s planets are lining up to parade through the night sky at once. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known as a ...

Especially since all seven of the other planets in our solar system are about to become visible at once in a great planetary alignment. According to New Scientist: “The great alignment, including ...

Stargazers will be treated to a rare seven-planet alignment in February. This is what scientists hope to learn.

The enormous visitor to our solar system may have been about 8 times the mass of Jupiter, and come nearly as close to the sun ...

Stargazers will be treated to a dazzling six-planet "alignment" this January.

A very rare treat is about to grace Earth's night skies.

This, of course, never happened as a result of the fictional world not being real ... everything in our solar system, thanks to the gas giant planet’s being larger than all the other planets ...

While the composition of gas and dust in a molecular cloud is fairly uniform, everything changes once a star begins to form.

Six planets are parading across the sky, appearing as some of the night's brightest stars. A few easy tips can help you ...

Though the planets are always “aligned ... will begin to reveal these ice giants at the edge of the solar system as tiny disks. All seven worlds and the moon appear strung along a line ...

Computer simulations of the gravitational interactions of solar system bodies suggest that a hypothetical Earth-like planet explains all of those anomalies. It would need to be around 1.5–3 ...