For as long as we have looked up at the stars, we have wondered if we are alone in the universe. We have searched for signals, looked at distant planets, and explored our own solar system. For many years, most of this search focused on planets like Mars. But in recent decades, scientists have turned … Read more
For the first time in over fifty years, humans are going back to the Moon. This time, it is not just to visit. NASA’s Artemis program is a new generation of missions with a huge goal: to build a long-term human presence on the Moon. This means learning to live and work on another world. … Read more
Mars has captured our attention for centuries. We see it as a glowing red dot in the night sky, and we have sent rovers and orbiters to explore its dusty, rocky landscape. We often talk about it as a potential future home for humans or wonder if life once existed there. The rovers we send … Read more
In the cold, dark, outer reaches of our solar system, orbiting the giant planet Jupiter, is a small, bright moon called Europa. At a glance, it looks like a smooth, white billiard ball, covered in long, dark cracks. But for decades, scientists have looked at this icy world and become more and more convinced that … Read more
When we look at Mars today, we see a cold, dry, and dusty red desert. Its atmosphere is incredibly thin, and any water on the surface is frozen solid as ice. It is a harsh and empty world. But science tells us that this was not always the case. Billions of years ago, the Mars … Read more
When we look at our solar system, Earth stands out as a beautiful blue marble, covered in water. Its neighbor, Venus, is a very different place. Often called Earth’s “twin” because it is a similar size, Venus today is a scorching, toxic world. It is the hottest planet in our solar system, with a thick, … Read more
When we look at our solar system, we see a family of planets, each with its own personality. We have the giant, gassy Jupiter, the ringed beauty Saturn, and our own blue, watery Earth. Then there is Mercury. It is the smallest planet in the solar system, not much bigger than Earth’s Moon. It is … Read more
The first solid clues for Dark Matter came from studying how galaxies rotate. Imagine a merry-go-round; the objects close to the center spin faster than those on the outer edge. We would expect the same in a galaxy: stars closer to the center, where most of the visible mass is concentrated, should orbit faster than … Read more
Our solar system is a familiar place. We learn about the eight planets in school, from rocky Mercury near the Sun to gassy Neptune far away. For a long time, astronomers felt they had a good map of our cosmic neighborhood. After Pluto was reclassified as a dwarf planet, the map seemed complete. We had … Read more
The Moon is the most familiar object in our night sky. It floats above us, changing its shape throughout the month, and has been a source of wonder for all of human history. For a very long time, people looked up and wondered where it came from. Because the Moon is so large compared to … Read more