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Neptune
Neptune has celebrated
its first birthday - on 12 July. It became one Neptunian year or 164.79 Earth years
old since its discovery on September 24, 1846. But we still know so little about
this distant planet.
It lies at the distance of
about 4.4 billion kilometers from Earth, the first planet in the solar system to be
discovered deliberately. After the classification of the planet Uranus in the 1780s,
astronomers had been perplexed by its strange orbit. Scientists came to the conclusion
that either Isaac Newton's laws were fundamentally flawed or that something else or some
"another planet" was pulling Uranus from its expected orbit.
And so the search for the eighth planet began -----
It was such an incredible mathematical business, that it was like searching for a needle
in a haystack. Although it looked like a 10-minute job for a child". While mathematical
predictions had been made over the previous decades, it was not until French mathematician
Urbain le Verrier's theories were tested at the Berlin observatory by Johann Gottfried Galle
that the planet was first seen. After only an hour or so of searching, Neptune was observed
for the first time on the night of 23 September 1846. It was found almost exactly where le Verrier
had predicted it to be - so surprising. Although independently, British scientist John Couch
Adams also produced similar results, so he and Verrier are given joint credit for the discovery
of Neptune.
Galileo is also known to observe Neptune
more than 200 years before its existence was confirmed, but many claim that it was not Galle who
documented the planet first, but the famous astronomer and mathematician Galileo. In his famous work
"The Starry Messenger", some evidence points to his discovery.
Unfriendly Lump of Frozen Gases
Part of the problem is that there is no way for the planet to be viewed with the naked eye
and until the Hubble telescope, its scientific observation was very difficult. So what is
Neptune like? "It is a frozen lump of frozen gases and not a terribly friendly place,"
says Dr Chapman. Although we can wish it a happy birthday but perhaps we should keep as far
away from it as we can as it won't give us a warm welcome (maybe very frozen welcome).
One of the most interesting things
for scientists about Neptune is its wild weather. Cloudy with a chance of methane gas is how
planetary scientist Heidi Hammel, of the Association of Universities for Research in Astronomy
(Aura), describes it. Winds can reach up to 1,930 km/h (1,200 mph), creating storms unimaginable
on Earth. These huge storms are seen as dark spots in a similar way to the Great Red Spot on
Jupiter.
The reason astronomers know so
little about it, is because the planet has only been photographed once from close range, on
the Voyager 2 mission in 1989. And because its seasons last 40 Earth years, only Neptune's
spring and early summer have been closely documented. Every time we go to a telescope and
look at this planet, it is doing something new, it is doing something we hadn't thought of
before," says Dr Hammel. What Dr Hammel found was that storms were appearing and forming
and changing much more quickly than had previously been thought. She was looking at a planet
very different from the photos taken by Voyager 2. "We really have only been observing
Neptune with big telescopes since shortly before 1989," she says, "We haven't been
looking long enough. This planet is not for the impatient.
We know how it fits into
the sequence of planets as far as composition goes but we don't know a lot about it.
Following the Pluto's declassification in 2006, Neptune is now the outermost planet
in the solar system. People are trying to question whether Pluto could be reclassified
as the ninth planet in the solar system after its primary planet title was taken away
in 2006. If it was reinstated, Neptune would lose the honor of being the furthest planet
from the Sun. Whether Pluto is called a planet or not is a matter of semantics,"
says Dr Catchpole. The situation with the classifications is that Pluto doesn't fit into
the current system very well. I don't think it is ever going to change again.
So happy birthday Neptune.
Though lighting any candles on a birthday cake might be tricky in those high winds.
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