Top 15 amazing facts about solar system | 15 interesting facts | amazing solar planets facts

Top 15 amazing facts about solar system | 15 interesting facts | amazing solar planets facts

This artist’s concept puts solar system distances in
perspective. The scale bar is in astronomical units, with
each set distance beyond 1 AU representing 10 times the
previous distance. One AU is the distance from the sun to
the Earth, which is about 93 million miles or 150 million
kilometers. NASA’s Voyager 1, humankind’s most distant
spacecraft, is around 125 AU. Image via NASA/JPL-
Caltech.
1. The hottest planet isn’t closest to the sun. Many people
know that Mercury is the closest planet to the sun, well
less than half of the Earth’s distance. It is no mystery,
therefore, why people would assume that Mercury is the
hottest planet. We know that Venus, the second planet
away from the sun, is on the average 30 million miles
farther from the sun than Mercury. The natural assumption
is that being farther away, it must be cooler. But
assumptions can be dangerous. For practical consideration,
Mercury has no atmosphere, no warming blanket to help it
maintain the sun’s heat. Venus, on the other hand, is
shrouded by an unexpectedly thick atmosphere, about 100
times thicker than our own on Earth. This in itself would
normally serve to prevent some of the sun’s energy from
escaping back into space and thus raise the overall
temperature of the planet. But in addition to the
atmosphere’s thickness, it is composed almost entirely of
carbon dioxide, a potent greenhouse gas. The carbon
dioxide freely lets solar energy in, but is far less
transparent to the longer wavelength radiation emitted by
the heated surface. Thus the temperature rises to a level
far above what would be expected, making it the hottest
planet. In fact the average temperature on Venus is about
875 degrees F, hot enough to melt tin and lead. The
maximum temperature on Mercury, the planet closer to the
sun, is about 800 degrees F. In addition, the lack of
atmosphere causes Mercury’s surface temperature to vary
by hundreds of degrees, whereas the thick mantle of
carbon dioxide keeps the surface temperature of Venus
steady, hardly varying at all, anywhere on the planet or any
time of day or night!
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2. Pluto is smaller than the USA. The greatest distance
across the contiguous United States is nearly 2,900 miles
(from Northern California to Maine). By the best current
estimates, Pluto is just over 1400 miles across, less than
half the width of the U.S. Certainly in size it is much
smaller than any major planet, perhaps making it a bit
easier to understand why a few years ago it was “demoted”
from full planet status. It is now known as a “dwarf planet.”
3. George Lucas doesn’t know much about “asteroid
fields.” In many science fiction movies, spacecraft are
often endangered by pesky asteroid fields. In actuality, the
only asteroid belt we are aware of exists between Mars
and Jupiter, and although there are tens of thousands of
asteroids in it (perhaps more), they are quite widely spaced
and the likelihood of colliding with one is small. In fact,
spacecraft must be deliberately and carefully guided to
asteroids to have a chance of even photographing one.
Given the presumed manner of creation, it is highly unlikely
that spacefarers will ever encounter asteroid swarms or
fields in deep space.
4. You can make volcanos using water as magma. Mention
volcanoes and everyone immediately thinks of Mount St.
Helens, Mount Vesuvius, or maybe the lava caldera of
Mauna Loa in Hawaii. Volcanos require molten rock called
lava (or “magma” when still underground), right? Not really.
A volcano forms when an underground reservoir of a hot,
fluid mineral or gas erupts onto the surface of a planet or
other non-stellar astronomical body. The exact composition
of the mineral can vary greatly. On Earth, most volcanoes
sport lava (or magma) that has silicon, iron, magnesium,
sodium, and a host of complicated minerals. The volcanoes
of Jupiter’s moon Io appear to be composed mostly of
sulfur and sulfur dioxide. But it can be simpler than that.
On Saturn’s moon Enceladus, Neptune’s moon Triton, and
others, the driving force is ice, good old frozen H 20! Water
expands when it freezes and enormous pressures can build
up, just as in a “normal” volcano on Earth. When the ice
erupts, a “cryovolcano” is formed. So volcanoes can
operate on water as well as molten rock. By the way, we
have relatively small scale eruptions of water on Earth
called geysers. They are associated with superheated water
that has come into contact with a hot reservoir of magma.