Neptune: The furthest planet from our sun
Neptune is the farthest planet from the sun and one of the two “ice giants” of our solar system. The cold, blue planet is about 30 times farther from the sun than Earth and takes about 165 Earth years to complete a single orbit around our star. Neptune spins around its axis faster than Earth, so a day on Neptune lasts only about 16 Earth hours.
When was Neptune discovered?
Scientists discovered Neptune in 1846, after performing orbit calculations for Uranus which indicated that there was an unknown planet affecting the planet Uranus. gravityaccording to Natural History Museum (opens in a new tab) in London, UK, Neptune is not visible to the naked eye, but researchers were able to confirm the existence of the planet using a telescope. Astronomers had already spotted Neptune through telescopes as early as 1612, but hadn’t identified it as a planet, according to Nasa (opens in a new tab).
Only one of Earth’s probes has ever reached Neptune – Voyager 2, which took the first images of the blue planet in 1989 as it exited the solar system. Neptune appears blue, or blue-green, because of methane in its atmosphere, according to Smithsonian National Air and Space Museum (opens in a new tab) in Washington DC The name Neptune comes from the Roman sea god of the same name, according to fresh cosmos (opens in a new tab)a website operated by the California Institute of Technology Infrared Processing and Analysis Center.
Related: Mercury probe takes stunning photos of our planet during Earth flyby
How long would it take to get to Neptune?
Neptune is the eighth planet from the sun and the last planet in the solar system, since scientists downgraded Pluto from full planetary status to dwarf planet in 2006. Neptune is also the farthest planet in the solar system from Earth and orbits at a distance between 2.7 billion miles (4.3 billion km) and 2.9 billion miles (4.7 billion km) from our planet, depending on where the two planets are in their orbits, Live Science partner site Space.com previously reported. The Voyager 2 probe took 12 years to reach Neptune, according to NASA Jet Propulsion Laboratory (opens in a new tab). However, the probe was moving at an average speed of 42,000 mph (about 68,000 km/h) – much faster than humans have ever travelled.
What is the temperature of Neptune?
The temperature in Neptune’s atmosphere is around minus 373 degrees Fahrenheit (minus 225 degrees Celsius), according to the National Air and Space Museum. Being farther from the sun than Uranus, you might expect Neptune to be colder, but the two planets are about the same temperature. Neptune emits more than twice as much heat as it absorbs from the sun, like Jupiter and Saturn, Live Science previously reported.
“The additional heat source on Neptune [and Jupiter and Saturn] is largely due to gravitational contraction,” said Joshua Tollefson, a data scientist formerly at the University of California, Berkeley. Magazine All About Space (opens in a new tab) in 2019. “As the planet slowly contracts gravitationally, material falling inward changes its potential energy into thermal energy, which is then released upwards out of the planet.
Neptune also has the strongest winds in the solar system, which can reach 1,200 mph (1,9301 km/h), according to Cool Cosmos. Seasons on Neptune last about 40 years each, and the planet’s southern hemisphere is currently in Earth’s equivalent of summer. However, a 2022 study published in The Journal of Planetary Science (opens in a new tab) used infrared images of the planet to determine that despite entering summer in 2005, Mercury’s global temperature actually dropped 14.4 F (8 C) between 2003 and 2018. The researchers released the assumption that the falling temperatures in Neptune’s atmosphere could be caused by either an unidentified element, extreme weather conditions or changes in solar radiation.
“I think Neptune itself is very intriguing to many of us because we still know so little about it,” said study lead author Michael Roman, an astronomer at the University of Leicester in the UK. statement (opens in a new tab) at the time. “All of this points to a more complicated picture of Neptune’s atmosphere and how it changes over time.”
Related: The sun blew Mercury out with a plasma wave
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What is Neptune made of?
Neptune is mostly water, ammonia and methane and could be hiding a “super hot” ocean beneath its cold clouds, according to NASA. The planet has no solid surface, but has a solid core like Earth. In the same way Uranus, Neptune is called an “ice giant”. The name distinguishes Neptune from the “gas giants” of Jupiter and Saturn because Neptune and Uranus have more ice-forming molecules, according to the Planetary society (opens in a new tab).
Neptune and Uranus are famous for their “diamond rain.” This is possible because the high atmospheric pressure on these planets – which is more than 200,000 times that on Earth – breaks down methane in the atmosphere to release carbon. The carbon then groups together in long chains to form crystalline patterns like diamonds. These “diamonds” sink through the mantle, where they are vaporized by even more extreme conditions – the deepest regions of the mantles of these planets probably reached around 12,140 F (6,727 C) with pressures 6 million times higher than those on Earth – before rising again for the process to repeat, Live Science previously reported.
Does Neptune have moons?
Neptune has 14 moons and at least five rings. Triton, the largest of Neptune’s moons, orbits in the opposite direction to the rotation of the planet. This reverse orbit indicates Triton was not always associated with Neptune, and scientists believe it was pulled into Neptune’s gravity from the Kuiper Belt millions of years ago, according to Nasa (opens in a new tab).
Nereid, another of Neptune’s moons, has an even more peculiar orbit, making it one of the strangest moons in the solar system. This moon can approach Neptune at a distance of 870,000 miles (1.4 million km) and move away up to 6 million miles (9.7 million km). One reason for this strange lunar orbit could be that when Triton was pulled towards Neptune, it rejected the orbits of Neptune’s existing moons and sent most of them into space. However, Nereid could be an original moon that clung to the edge of Neptune’s gravity to shape its current orbit.
Related: Neptune’s flickering moons are locked in a never-before-seen orbital dance
To see images of Neptune taken by the Voyager 2 probe, see NASA Jet Propulsion Laboratory (opens in a new tab) website. To learn more about the diamond shower on Neptune and Uranus, watch this short YouTube video by the astrophysicist and Live Science contributor Paul M. Sutter (opens in a new tab). For a children’s book on Neptune, see “The Secrets of Neptune (opens in a new tab)(Capstone Press, 2015).
Originally posted on Live Science.