Mercury and Venus are the only two planets in our solar system that have no moons. In total, there are 176 confirmed moons that orbit the planets in our solar system, with some of them being bigger than Mercury itself.
If a star passes too close to a black hole, it can be torn apart. For 20 years, a team of astronomers observed a star at the center of our galaxy orbiting a black hole. The star has now gotten close enough to the black hole for "gravitational redshift" to occur, which is where the star's light loses energy as the black hole's gravity intensifies.
The hottest planet in our solar system is Venus. Most people think that it would be Mercury as it is closest to the sun. However, Venus has a lot of gases in its atmosphere which creates a greenhouse effect that causes a constant temperature of 864 degrees Fahrenheit or 462 degrees Celsius everywhere on the planet's surface.
Our solar system is 4.57 billion years old. Scientists estimate that in about five billion years, the sun will expand, becoming a red giant. In about 7.5 billion years, its expanding surface will swallow up and engulf the Earth.
Enceladus
One of Saturn's smaller moons, Enceladus, reflects 90 percent of the sun's light. This is because Enceladus' icy surface reflects the sunlight rather than absorbing it. Temperatures can therefore reach as low as 394 degrees Fahrenheit or 201 degrees Celsius.
Olympus Mons
The highest mountain discovered is Olympus Mons, which is located on Mars. Its peak is 16 miles or 25 kilometers high, making it nearly three times higher than Mount Everest. It is not only tall but also 374,000 square feet or 114,000 square meters wide, which is an area the size of Arizona.
Whirlpool Galaxy M51
The Whirlpool Galaxy M51 was the first celestial object identified as being a spiral. The grand spiraling arms of the Whirlpool Galaxy are made up of long lanes of stars and gas sprinkled with lots of space dust. These arms act as star formation factories, compressing hydrogen gas and creating clusters of new stars.
The Milky Way
The Milky Way is 105,000 light-years wide. It would take a modern spacecraft 450 million years to travel to the center of our galaxy.
The Sun
The sun weighs about 330,000 times more than Earth. It is about 109 times the diameter of Earth and is so large that Earth could fit inside the sun about one million three hundred thousand times over. In fact, the sun contains 99.85% of all mass in our solar system.
The Moon
Footprints left on the moon won't disappear as there is no wind. Because of the lower gravity, a person who weighs 220 lbs on Earth would weigh 84 pounds on Mars.
Jupiter
There are 79 known moons orbiting Jupiter. Jupiter is the planet in our solar system with the most moons, and it also has the largest moon in our solar system. That moon is called Ganymede and is 33,279 miles or 5,000 kilometers in diameter, which is bigger than Mercury and can be seen with just a pair of binoculars.
The Moon's Water
NASA's Crater Observation and Sensing Satellite (LCROSS) found evidence of water on the Earth's moon. While water cannot exist on the moon's surface under its current conditions, scientists believe water ice could survive within the cold permanently shadowed craters at the moon's two poles.
Pluto
Pluto is smaller than the United States. If you were to walk around the equator of Pluto, it would be the same distance as walking from London to Denver. According to mathematics, white holes are possible, although as of yet, we have found none. A white hole is a hypothetical region of spacetime which can't be entered from the outside, although matter and light can escape from within. Basically, it's the reverse of a black hole.
Venus
There are more volcanoes on Venus than any other planet in our solar system. There are more than 1600 major volcanoes across the surface of Venus, including a 5-mile or 8-kilometer high volcano called Maat Mons. However, none of these volcanoes are known to be erupting at present, and most are probably long extinct.
Uranus
Uranus'
If you were to drive around Saturn's rings at a speed of miles per hour, it would take you 258 days to complete the journey. Saturn's rings have a length of roughly 175,000 miles, although they are only about 3,200 feet thick.
Outer space is just 62 miles away from us. While there is no solid boundary that marks the beginning of space, the Karman line is commonly used at 62 miles above sea level as a reference point. This line is used in space treaties and aerospace record-keeping.
The International Space Station (ISS) completes one orbit around Earth every 92 minutes. The speed of the ISS as it orbits Earth is approximately 17,000 miles per hour, which is equivalent to 5 miles per second.
