German astronomer Johann Galle used calculations to help find Neptune in a telescope. Irregularities in the orbit of Uranus led French astronomer Alexis Bouvard to suggest some other might be exerting a gravitational tug. Neptune was the first planet to be predicted to exist by using mathematics, before it was detected. The planet is more than 30 times as far from the sun as Earth. The eighth planet from the sun, Neptune is known for strong winds - sometimes faster than the speed of sound. Named for: Personification of heaven in ancient myth It has numerous moons and faint rings.ĭiscovery: 1781 by William Herschel (was thought previously to be a star) Methane in the atmosphere gives Uranus its blue-green tint. Uranus is about the same size as Neptune.
The tilt causes extreme seasons that last 20-plus years, and the sun beats down on one pole or the other for 84 Earth-years. Astronomers think the planet collided with some other planet-size object long ago, causing the tilt. It’s the only giant planet whose equator is nearly at right angles to its orbit - it basically orbits on its side. The seventh planet from the sun, Uranus is an oddball. The gaseous planet is mostly hydrogen and helium. Scientists are not yet sure how they formed. More than 40 years later, Christiaan Huygens proposed that they were rings. Not knowing he was seeing a planet with rings, the stumped astronomer entered a small drawing - a symbol with one large circle and two smaller ones - in his notebook, as a noun in a sentence describing his discovery. When Galileo Galilei first studied Saturn in the early 1600s, he thought it was an object with three parts. The sixth planet from the sun is known most for its rings. Jupiter has a strong magnetic field, and with dozens of moons, it looks a bit like a miniature solar system. A big feature is the Great Red Spot, a giant storm which has raged for hundreds of years. Its swirling clouds are colourful due to different types of trace gases. It’s a mostly gaseous world, mostly hydrogen and helium. The fifth planet from the sun, Jupiter is huge and is the most massive planet in our solar system. Scientists think ancient Mars would have had the conditions to support life, and there is hope that signs of past life - possibly even present biology - may exist on the Red Planet.ĭay: Just more than one Earth day (24 hours, 37 minutes) Jupiter Mars' atmosphere is too thin for liquid water to exist on the surface for any length of time. Scientists think it was once wet and warm, though today it’s cold and desert-like. Mars shares similarities with Earth: It is rocky, has mountains and valleys, and storm systems ranging from localized tornado-like dust devils to planet-engulfing dust storms. The dust, an iron oxide, gives the planet its reddish cast. The fourth planet from the sun, is a cold, dusty place. The planet zips around the sun at more than 18 miles per second (29 km per second). Earth's surface rotates about its axis at 1,532 feet per second (467 meters per second) - slightly more than 1,000 mph (1,600 kph) - at the equator. Earth’s atmosphere is rich in life-sustaining nitrogen and oxygen. It’s the only world known to harbor life. The third planet from the sun, Earth is a waterworld, with two-thirds of the planet covered by ocean. Named for: Roman goddess of love and beauty Because it is often brighter than any other object in the sky - except for the sun and moon - Venus has generated many UFO reports. The Greeks believed Venus was two different objects - one in the morning sky and another in the evening. Its size and structure are similar to Earth, Venus' thick, toxic atmosphere traps heat in a runaway "greenhouse effect." Oddly, Venus spins slowly in the opposite direction of most planets. Scientists describe Venus’ situation as a runaway greenhouse effect. The pressure at the surface would crush and kill you.
The second planet from the sun, Venus is terribly hot, even hotter than Mercury. Over its four-year mission, NASA's MESSENGER spacecraft has revealed views of the planet that have challenged astronomers' expectations.ĭiscovery: Known to the ancients and visible to the naked eye Mercury has virtually no atmosphere to absorb meteor impacts, so its surface is pockmarked with craters, just like the moon. Its day side is scorched by the sun and can reach 840 degrees Fahrenheit (450 Celsius), but on the night side, temperatures drop to hundreds of degrees below freezing. The closest planet to the sun, Mercury is only a bit larger than Earth's moon.
0 kommentar(er)
