Tag Archives: moon

Pluto: The former planet still fascinates and intrigues

Pluto with moons:  Charon, Nix and Hydra

Pluto with moons: Charon, Nix and Hydra

Fun Facts About Pluto

 

1. Pluto has an atmosphere

Even though Pluto’s average temperature averages a mere 44 degrees above absolute zero, the dwarf planet has an atmosphere. Not an atmosphere as we know it, but an atmosphere, none the less.

It was first discovered back in 1985, when astronomers watched as Pluto passed in front of a star. They were able to calculate a slight dimming as its atmosphere passed in front of the star, before Pluto itself blocked the star entirely. From those observations, they were able to calculate that it has a thin envelope of nitrogen, methane and carbon dioxide.

As Pluto moves away from the Sun, this atmosphere gets so cold that it freezes onto the surface. And then as the dwarf planet warms again, the atmosphere evaporates again, forming a gas around it.

2. Pluto has 3 moons

You might have heard that Pluto has a large moon called Charon, but did you know that it actually has 3 moons in total. Charon is the large one, with a mass of roughly half that of Pluto’s.

Two additional moons, Nix and Hydra, were discovered by astronomers using the Hubble Space Telescope on May 15, 2005. They were originally called S/2005 P1 and S/2005 P2, and then given their final names on June 21, 2006.

They took a long time to discover because they’re so tiny. Nix is only 46 km across, while Hydra is 61 km across.

3. Pluto hasn’t cleared out its orbit

Although Pluto orbits the Sun and it’s round, it’s not a planet. And that’s because Pluto hasn’t cleared out its orbit of material. This was the reason that the International Astronomical Union chose to demote it from planet to dwarf planet in 2006.

Just to give you an idea, if you added up the mass of all the other objects in Pluto’s orbit, Pluto’s mass would only be a tiny fraction of that total. In fact, it would only be 0.07 times as massive as everything else. For comparison, if you did the same thing with all the other material in the Earth’s orbit, our planet would be 1.5 million times as massive.

And that’s why Pluto’s not a planet.

4. Pluto is actually a binary system


You’d think that Charon orbits Pluto, but actually, Pluto and Charon orbit a common point in space. In the case of the Earth and the Moon, we actually orbit a common point, but that spot exists inside the Earth. In the case of Pluto and Charon, however, that common point is above the surface of Pluto.

Before Pluto was downgraded to a dwarf planet, astronomers were thinking of classifying it as a binary planet system. And then as a binary dwarf planet system. Perhaps that will help it recover some of its lost glory.

5. Pluto is named after a god, not a dog

If you think Pluto is named after a Disney character, you’re wrong. It’s actually named after the Roman god of the underworld. And Charon is the ferryman who carries souls across the river Styx.

When it was first discovered, Pluto was just given the name Planet X, but then the discoverers needed to come up with something better and more permanent. The name Pluto was suggested by Venetia Burney, an 11-year old school girl in Oxford, England. She thought it was a good name for such a cold, dark world. It was passed along to the discoverers and they liked it enough to make it official.

6. Pluto can be closer than Neptune

For most of its orbit, Pluto is more distant than Neptune, reaching out as far as 49 astronomical units (49 times the distance from the Earth to the Sun). But it has such an eccentric, elliptical orbit that it gets much closer, reaching a mere 29 AU. And during that time, it’s actually orbiting within the orbit of Neptune. The last time Pluto and Neptune made this switch was between February 7, 1979 and February 11, 1999. And give it another couple of hundred years and it’ll happen again.

7. Pluto is smaller than any planet, and even 7 moons

Pluto is small. How small? Astronomers recently calculated that its mass is 1.31 x 1022 kg (less than 0.24% the mass of Earth). And its diameter is only 2,390 km across.

At this point, it’s smaller than Mercury, and seven other moons including: Ganymede, Titan, Callisto, Io, Earth’s Moon, Europa, and Triton.

And now astronomers know that it’s even smaller than the recently discovered dwarf planet Eris. Here’s more information about how big Pluto is.

8. If it were closer to the Sun, Pluto would be a comet

Although this isn’t officially a reason for losing its planet status, Pluto wouldn’t last long if it got much closer to the Sun. It’s comprised of about half rock and half ice. This is a similar ratio to many rocky comets in the Solar System.

If you could somehow bring Pluto closer to the Sun, it would sprout a tail, becoming a spectacular comet. And over millions of years, the solar wind would blast away its icy structure, causing it to lose mass.

It’s lucky Pluto lives in such a cold, dark part of the Solar System.

9. Charon might have geysers

In the last few years, astronomers have discovered that several objects in the Solar System have ice geysers, including Saturn’s moon Enceladus, and maybe several others as well. But Pluto’s moon Charon could have this happening too.

Astronomers using the Gemini Observatory in Mauna Kea in Hawaii recently turned up evidence that geysers on Charon are spreading ammonia hydrates and water crystals across the surface of the moon.

Is this really happening? We’ll know soon, because… here’s the last Pluto fact.

10. There’s a spacecraft going to Pluto right now

NASA’s New Horizons spacecraft is making its way to Pluto right now. The spacecraft launched in 2005, and its expected to reach the dwarf planet in 2015. It will pass right through the system, imaging the surface of Pluto and its moons, and finally answering questions that have puzzled astronomers for nearly a hundred years.

 

Special thanks to www.universetoday.com

Leave a comment

Filed under Science

Stonehenge: Ancient Monument, Astronomical Observatory or Something Else?

The Rock Pillars of Stonehenge

The Rock Pillars of Stonehenge

 

Fun Facts About Stonehenge

 

  • Stonehenge is located on the Salisbury Plain in Wiltshire, England – about 137 kilometers Southwest of London.
  • The origins of the name Stonehenge is taken from the combination of ‘stone’ and ‘henge’, a tribute to the biggest henge in Britain.
  • Though there is no specific evidence about who built the Stonehenge. It is believed that Druids, Greeks, or Atlanteans might have built the Stonehenge.
  • Stonehenge was constructed somewhere between 3100 – 1100 BCE.
  • On September 21st, 1915, C.H. Chubb purchased Stonehenge for 6,600 pounds
  • Stonehenge and its surroundings were added to the UNESCO’s list of World Heritage Sites in 1986 and is also legally protected by the Scheduled Ancient Monument.
  • Stonehenge is owned by the Crown and managed by English Heritage while the surrounding land is owned by the National Trust.
  • The circle was aligned with the midsummer sunrise, the midwinter sunset, and the most southerly rising and northerly setting of the moon.
  • The builders of Stonehenge have featured it in a way that it encompasses sophisticated mathematical and geometrical understandings of the framework and the structural engineering of the construction.
  • Stonehenge has a henge, or a ditch and bank, which surround the large stone circle.
  • The stones of Stonehenge were placed in such a way that they increase in size towards the centre and alternate in shape between tall, thin pillar-like stones and stones of a tapering obelisk shape.
  • Two types of stone were used for the construction of Stonehenge- the ‘bluestones’ which weighed almost four tons and were brought from 240 miles away. The other type of stone used was the ‘Sarsen’ stones which had a height of about eighteen feet and weighed twenty-five tons.
  • It is anticipated that more than thirty million hours of labor was required for the construction of Stonehenge.
  • Stonehenge is the most well known among the nine hundred stone rings which exists in the British Isles.
  • Most archaeologists believed that Stonehenge’s use had been limited to the ritual activities of different Neolithic chiefdoms before 1950. However, its use as an astronomical observatory was an equally important function of the Stonehenge.
Special thanks to www.iloveindia.com

 

Leave a comment

Filed under Nature, Science, Travel