Happy Independence Day! If you’re celebrating the 4th of July by attending a fireworks display, maybe you’ll look up and wonder: What creates those red, orange, yellow, green, blue and purple colors exploding in the night sky?
Happy birthday to all you July babies! Your birthstone, the ruby, is among the most highly prized of gemstones. Large rubies are harder to find than large diamonds, emeralds and sapphires. As a result, rubies’ value increases with size more than any other gemstone.
Asteroids tend to be rockier or more metallic. Comets tend be icier. But some objects blur the distinction between asteroids and comets.
It is indeed possible to see the whole circle of a rainbow – but conditions have to be just right.
The longest day of the year comes at the summer solstice, but the hottest weather always follows a month or two later. Why? The phenomenon of the hot weather following the summer solstice by a month or two is called the lag of the seasons.
It’s common knowledge that our moon has a nearside and a farside. One half of the moon always faces Earth, and one half always points away. Does this mean we can only see 50% of the moon’s surface from Earth? No. In fact, over time, it’s possible to see as much as 59% of the moon’s surface, due to a slight north-south rocking and east-west wobbling of the moon known as lunar libration. Follow the links inside to learn more.
Fireflies are sometimes called lightning bugs. Many a child has spent a summer evening chasing them. And maybe you’ve wondered – how and why are these insects able to light up?
Scientists agree that there’s oxygen from ocean plants in every breath we take. Most of this oxygen comes from tiny ocean plants – called phytoplankton – that live near the water’s surface and drift with the currents. Like all plants, they photosynthesize – that is, they use sunlight and carbon dioxide to make food. A byproduct of photosynthesis is oxygen. Scientists estimate that phytoplankton contribute between 50 to 85 percent of the oxygen in Earth’s atmosphere.
Mars is the world orbiting the sun one step outward from Earth’s orbit. Earth takes one year to orbit the sun once. Mars takes about two years. The orbits of Earth and Mars are the reason Mars is one of the most fascinating planets to watch in our sky, and they are the reason Mars is sometimes bright and sometimes faint. On April 8, 2014, Earth went between the sun and Mars. That’s why Mars was so bright this past April.
Now Mars is fainter, but it still lovely to behold, and its near the moon on the night of June 6.
The brightness of Mars in our sky depends on where our two planets are in orbit around the sun. Sometimes Earth is close to Mars, and sometimes we are far away.
We are relatively close – and Mars appears at its brightest in our sky for that two-year period – every time Earth passes between the sun and Mars. That’s what’s happening today.
Ever wonder how hurricanes get their names? And why do hurricanes have names at all? Meteorologists long ago learned that naming tropical storms and hurricanes helps people remember the storms, communicate about them more effectively, and so stay safer if and when a particular storm strikes a coast. Find out more about hurricane names inside.