Sunday, October 4, 2009

What's Up? The Outer Solar System's Frigid, Yet Fierce Weather

Welcome back to What's Up?

Now that Summer has come to an end, the Athena Community Astronomy Club has wrapped up their weekly boardwalk viewings. Thanks to club members who made this possible and to everyone who dropped by to take a peek through one of the telescopes.

Although the weather wasn't great throughout the Summer, it doesn't even compare to the weather on other planets. Let's continue last month's tour of the weather on other planets in our solar system.

Last month we looked at the inner solar system, the rocky planets, and this month we'll continue to move outwards into the outer solar system.

Jupiter, the fifth planet from the Sun, is the largest planet in the solar system. If you were to take all of the planets, comets, and asteroids, and put them together, they would easily fit within Jupiter.

Jupiter's massive size also comes with intense weather. A normal wind-speed that you could expect "on" Jupiter (it is made of gas and has no solid surface) is about 360 km/h (225 mph). The fastest wind speed ever recorded on Jupiter was an astounding 620 km/h (390 mph). Combined with Jupiter's -150°C (-238°F) "surface" temperature, there would be one nasty windchill!

Category five hurricanes are dwarfed by all of Jupiter's storms. It's biggest storm is currently twice the volume of the Earth and has been going non-stop for at least 400 years! This storm has sustained wind-speeds of 430 km/h (270 mph)! Another thing to watch out for: lightning, and lots of it. From Jupiter's night side, space probes have watched some of the largest lightning storms ever seen.

Moving on to Saturn, the sixth planet from the Sun, and the second largest, is a planet with some of the fastest winds in the solar system. In many regions there are sustained winds of up to 1760 km/h (1100 mph)! Combined with it being a gas giant like Jupiter (no solid surface), intense lightning, and a frigid average temperature of -184°C (-300°F), Saturn is not a good place to plan this year's vacation!

The next planet from the Sun, Uranus, another gas giant, is the third largest planet and doesn't have much better weather than Saturn. Even though it is the second coldest planet, at -210°C (-350°F), it still boasts impressive wind-speeds of up to 825 km/h (515 mph).

Last but not least, Neptune, the eighth and final planet from the Sun, is also the coldest, with an average temperature of -220°C (-370°F)! For some reason that has eluded scientists so far, the coldest planet in the solar system also has the fastest winds. These winds blow around the planet at a break-neck speed of up to 2100km/h (1300 mph), almost 600 meters (1800 feet) per second!

Pluto, now a dwarf planet, is so small it barely holds on to an "atmosphere" that is 700,000 times thinner than the Earth's atmosphere. It is so cold here, -235°C (-390°F), that its atmosphere (mainly Nitrogen), literally freezes out of the sky and snows to the ground!

Before Pluto reminds us of our upcoming winter, let's check out what's up.

The Moon will be full October 4 and will diminish to a new Moon by October 18.

Jupiter will be in the South in the early evening sky, it will be the brightest "star-like" object in the sky.

In the morning sky, half an hour or so before sunrise, will be Venus, Saturn, and Mercury. Venus will be by far the brightest object in the sky (other than the Moon and the Sun). Saturn and Mercury will be fairly dim and hard to pick out, Mercury will be only staying around during early October. All three can be seen in the East.

The Athena Community Astronomy Club's monthly meeting will be held on the last Sunday of the month, October 25, at the Wilmot Community Centre in Summerside. It starts at 7pm and runs to 9pm. All guests are welcome.

The astronomy club's website, although a work in progress, is up and running. Check it out at:

Until next month, just look up!

Hey Kids...
Last month, NASA scientists announced the discovery of water on the Moon. The Moon rocks brought back in the 1960's contained no water but now the scientists have found water all over the Moon. It's not much, but it will be enough to allow future colonies on the Moon to mine water from the soil. People living on the Moon may seem pretty far off, but NASA is planning on returning people to the Moon by 2020. Living on the Moon may not be science fiction for much longer!


Laurel Kornfeld said...
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Laurel Kornfeld said...

Neptune is NOT the final planet from the Sun. Please do not blindly accept the controversial demotion of Pluto, done by only four percent of the IAU, most of whom are not planetary scientists.

Their decision was immediately opposed in a formal petition by hundreds of professional astronomers led by Dr. Alan Stern, Principal Investigator of NASA’s New Horizons mission to Pluto. You can find a copy of that petition here:
And you can find audio transcripts of the Great Planet Debate, held at the Johns Hopkins University Applied Physics Lab in August 2008, where both sides of this ongoing debate were discussed, here:

One reason the IAU definition makes no sense is it says dwarf planets are not planets at all! That is like saying a grizzly bear is not a bear, and it is inconsistent with the use of the term “dwarf” in astronomy, where dwarf stars are still stars, and dwarf galaxies are still galaxies. Also, the IAU definition classifies objects solely by where they are while ignoring what they are. If Earth were in Pluto’s orbit, according to the IAU definition, it would not be a planet either. A definition that takes the same object and makes it a planet in one location and not a planet in another is essentially useless.

Pluto is a planet because it is spherical, meaning it is large enough to be pulled into a round shape by its own gravity--a state known as hydrostatic equilibrium and characteristic of planets, not of shapeless asteroids held together by chemical bonds. These reasons are why many astronomers, lay people, and educators are either ignoring the demotion entirely or working to get it overturned. Using this broader definition gives our solar system 13 planets and counting: Mercury, Venus, Earth, Mars, Ceres, Jupiter, Saturn, Uranus, Neptune, Pluto, Haumea, Makemake, and Eris.

I am a writer and amateur astronomer and proud to be one of these people. You can read more about why Pluto is a planet and worldwide efforts to overturn the demotion on my Pluto Blog at