Stories tagged Neptune

Neptune Anniversary Images
Neptune Anniversary ImagesCourtesy NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Neptune arrived today at the same location in space where it was discovered nearly 165 years ago. To commemorate the event, NASA's Hubble Space Telescope took these "anniversary pictures" of the blue-green giant planet.

Neptune is the most distant major planet in our solar system (alas, poor Pluto). German astronomer Johann Galle discovered the planet on September 23, 1846. The planet is 2.8 billion miles (4.5 billion kilometers) from the Sun. Under the Sun's weak pull at that distance, Neptune plods along in its huge orbit, slowly completing one revolution approximately every 165 years. Due to this slow orbit, each of Neptune's "seasons" lasts for about 40 years.

The four Hubble images of Neptune were taken with the Wide Field Camera 3 on June 25-26, during the planet's 16-hour rotation. The snapshots were taken at roughly four-hour intervals, offering a full view of the planet. The images reveal high-altitude clouds in the northern and southern hemispheres. The clouds are composed of methane ice crystals.

Oct
05
2007

Hot spot: The south pole of Neptune is warmer than the rest of the planet, at least right now, because its orbit is so large and slow. That portion of the planet has summer for 40 years. (Photo courtesy of NASA)
Hot spot: The south pole of Neptune is warmer than the rest of the planet, at least right now, because its orbit is so large and slow. That portion of the planet has summer for 40 years. (Photo courtesy of NASA)
Here on Earth, our coldest spots are on the poles. But go to Neptune and you’re singing a whole new tune.

Scientists have found that one of the coldest planets in our solar system has an unusual hot spot: its south pole. But don’t break out the sunscreen, swimsuits and sunglasses too fast.

Temperatures at Neptune’s south pole are about 18 degrees warmer than any other part of the planet, but the average temperature on the planet is 320 degrees below zero. And you thought Minnesota winters are harsh. An international team of astronmers just announced their temperature findings from the planet.

So why the difference?

Neptune’s south pole has been receiving summer sunlight for about 40 years. It’s mostly a function of how slow seasons change in a planet orbiting so far from the sun.

The planet is 2.8 billion miles from the sun. One Neptune year -- the time that it takes to make one complete orbit of the sun – is about 165 Earth years. Currently it’s south pole is in position for the perpetual sunshine, but that will all change in another 80 years or so, when the pole is in its winter position.

The frigid temperatures are the result of the Neptune getting just 1/900th the amount of sunlight that hits the Earth. So you probably can leave the sunscreen at home if you ever head that way.