StarDate

The United States and China plan to build permanent bases on the Moon. For the people who inhabit those bases, daily life will be quite different from life on Earth. For starters, the Moon’s gravity is only one-sixth as strong as Earth’s. So just walking will take some getting used to — a big step inside the base could result in a bump on the head. There’s no air on the Moon. Without it, there’s an extreme range in temperature. At the equator, it can range from about 250 degrees Fahrenheit at noon,

By far the most numerous objects in the solar system are asteroids — chunks of rock, metal, and ice. Scientists have discovered more than 1.3 million of them. They range from a few feet across to a few hundred miles. Most of them reside in the asteroid belt, between the orbits of Mars and Jupiter. Until a few decades ago, the number of known asteroids was just a few thousand. But some asteroids can come close to Earth, possibly endangering our planet. So scientists launched big searches to find as

Attitudes can change. That’s as true in science as in anything else. Today, asteroids are considered some of the most interesting objects in the solar system. But that wasn’t always the case. They went from eagerly sought, to absolutely despised. In fact, one astronomer called them the “vermin of the skies.” Asteroids are chunks of rock, metal, and ice. Most of them reside in a wide belt between the orbits of Mars and Jupiter. Astronomers first began looking for something in that region in the early

Pollux, the brighter of the “twin” stars of Gemini, is a giant. It’s expanded to about nine times the diameter of the Sun — a beach ball to the Sun’s golf ball. That’s made Pollux much cooler than the Sun, so it looks orange. And it’s more than 30 times brighter than the Sun. Careful measurements of its diameter, combined with measurements of subtle “ripples” across its surface, have yielded the mass of Pollux as well: 1.9 times the Sun’s mass. Astronomers have combined that with measurements of its

The planets that flank Earth huddle close together in the dawn sky over the next few days. Venus and Mars are quite low in the east-southeast during the waxing twilight, so you need a clear horizon to spot them. And binoculars wouldn’t hurt. Venus is the second planet out from the Sun, Earth is third, and Mars is fourth. Their orbits are separated by tens of millions of miles. Yet all three worlds are inside the Sun’s “habitable zone.” That’s the distance from the Sun where the temperature is just