The three brightest objects in the night sky team up during the early morning twilight tomorrow: the Moon and the planets Venus and Jupiter. Venus is the “morning star,” to the upper right of the Moon. Slightly fainter Jupiter is to the lower left of the Moon. It’s quite low, so you need a clear horizon to spot it.

Venus and Jupiter are siblings – they were born from the same disk of material around the newborn Sun. So were Earth and the solar system’s other planets. Besides their parentage, though, Venus and Jupiter don’t have a lot in common.

Venus is a ball of rock a little smaller than Earth. It’s topped by clouds of sulfuric acid. They reflect most of the sunlight that strikes them, which is one reason Venus is so bright.

Another is its proximity: Venus is the second planet from the Sun, while Earth is the third. So Venus passes closer to us than any other planet.

Because Venus and Earth formed so close to the Sun, they’re made mainly of rock and metal. The young Sun blew away most of the lighter materials – gas and ice. So Venus is dense and heavy.

Jupiter formed much farther from the Sun, where it was much colder. It built a big core of heavy materials, then swept up a lot of gas, dust, and ice. It became the largest planet in the solar system – a dozen times the diameter of Venus, and almost 400 times its mass – the “big brother” to the rest of the planets.

More tomorrow.

Script by Damond Benningfield