Comparing Jupiter To Earth Reveals Wonders Of The Solar System

3 color view of Jupiter by NASA's Cassini space probe

3 color view of Jupiter by NASA's Cassini space probe

3 color view of Jupiter by NASA’s Cassini space probe

Since on January 5 Jupiter was at Opposition (Jupiter is opposite the sun in our sky) and 93 million miles closer to Earth than during the rest of its orbit I thought an article about the giant of our solar system was in order. For reference the Earth is approximately 93 million miles from the sun. Which is called an astronomical unit. So Jupiter is one AU closer to Earth than during the rest of its orbit this week. Now don’t get all excited about this, Jupiter’s average distance from the sun is 5.2 astronomical units. Yeah, our solar system is vast.

So what makes Jupiter so interesting? Well let’s take a look at some of the fascinating things scientists have discovered about the solar system’s big brother. Since we are all residents of Earth and are, therefore, most familiar with it I think a little comparison is in order just for the sake of understanding better what we are dealing with in Jupiter.

For starters the Earth is around 25000 miles in circumference and takes 24 hours to complete a rotation. This makes the speed at which the Earth turns on it’s axis 25000miles/24hr or approximately 1000 miles/hour. (NASA)

Compare this with Jupiter which is around 272,942.9 miles in circumference. Now for the astonishing part: Jupiter’s day is only 10 hours long! Every time I think about that it boggles my mind. Jupiter is so large 1000 Earths could comfortably fit inside and it completes a full rotation in less than half an Earth day. (NASA Jupiter Factsheet)

Now unlike the Earth which has a solid surface Jupiter is a gas giant, so all we see is the gaseous upper cloud decks of the behemoth planet. Because of this the surface of the equator rotates more rapidly than the poles resulting in different lengths of the day depending on your latitude. The day varies from approximately 9 hours and 56 minutes at the poles to approximately 9 hours and 50 minutes at the equator. (Caltech)

Which brings us to composition. We know the Earth has a solid surface, we walk on it every day. Granted 70% of the Earth’s surface is covered by vast and life giving oceans but we have dry land to walk on. Also our atmosphere is mostly Nitrogen (N2) a whopping 78% with Oxygen comprising 21% and only traces of other gasses.

Jupiter’s atmosphere is Hydrogen and Heilium. NASA doesn’t even give percentages. The Earth has an iron core with just a smidge of nickel. Jupiter’s core is predicted to either be a solid inner core about the size of earth or some speculate a ball of liquid hydrogen. Jupiter does, in fact, have a faint ring system, discovered in 1971 by the Voyager 1 spacecraft. The only ring the Earth has is an artificial one made by satellites we’ve launched.

Speaking of satellites, the Earth has one, our Moon. Jupiter has over 50 moons and while Jupiter itself cannot support life as we know it some of its many moons have liquid oceans under the surface and may support alien life.

Hurricanes on Earth last for a few weeks. The great red spot on Jupiter is an enormous storm 3X the size of Earth that’s been raging for hundreds of years and shows no sign of slowing down. Pretty amazing, if you ask me.

On Earth the gravitational constant is 9.8 m/s^2. On Jupiter the gravitational constant is 24.79 m/s^2 wow. this makes the escape velocity of Jupiter 134,664 mph. Again, wow. By comparison the escape velocity of Earth is 25.031mph and look at the size of the rockets we have to build to get going just that fast.

Ok just one more fact comparison, because it’s fun and fascinating. The Earth’s revolves around the sun in 1 Earth year, which is 365 of our days. Our average orbital velocity is 66.622mph. Jupiter revolves around the sun in 1 Jovian year which is 12 Earth years. Compared to the Earth, Jupiter’s orbital velocity is a leisurely 29.205mph. The big planet is farther away from the sun and as a result doesn’t orbit as quickly around the Sun as the Earth.

And one last fact about Jupiter, at 5.2 AU from the sun Jupiter radiates more energy than it receives from the sun. That is amazing! Not a star but an almost star. If it had been but 80X more massive it would have ignited fusion in its core. (NASA Solar System Exploration)

So since Jupiter is at Opposition this week it’ll be at it’s brightest for skywatchers. Go, take a look and marvel at the wonders of our universe. K.

Ursid Meteor Shower Peaks This Weekend & Other Astronomy

Black Hole Chandra X-Ray Observatory NASA

Black Hole Chandra X-Ray Observatory NASA

Black Hole Chandra X-Ray Observatory NASA

That’s right my skywatching readers. The Ursid meteor shower peaks this weekend. The Ursid meteors come from the debris trail of comet P/8 Tuttle which has a period of 13.5 years. The Earth passes through the debris from the comet’s path around the sun every year around the winter solstice.

You know, I have been focusing on things that happen in our own solar system and the reason for that is that these are things we can see. The average, casual skywatcher can see these things. You don’t need a multi-million dollar telescope or access to the Hubble telescope to see them and that makes it exciting and accessible.

That being said, there have been some amazing discoveries outside of our humble solar system this year. NASA’s Kepler telescope has been searching for Earth-like planets that orbit in their star’s habitable zone and there are over 3000 contenders at last count. These are exciting times for skywatches and those who are interested in astronomy.

NASA’s Chandra X-Ray observatory has a facebook page where they post exquisite images and fascinating facts. There are still the free books from NASA chock full of gorgeous images from the Hubble Space Telescope. Wander on over to the website and feast your eyes while you feed your mind.

How Did I Miss Zooniverse?

Hubble Image of Magellanic Stream courtesy of NASA

Hubble Image of Magellanic Stream courtesy of NASA

Hubble Image of Magellanic Stream courtesy of NASA

Those of you who follow my blog must know that I love astronomy. I am endlessly fascinated by the grander, the beauty and the vastness of outer space. There is so much for us to learn, so many things to discover and each one is more fantastic, more breathtaking than the last it seems.

So how is it that I have only just discovered Zooniverse? I don’t know. This is a terrible oversight and I am very grateful to my friend for telling me about it. It’s a citizen science project that makes astronomy accessible to anyone with the interest. There is even an advent calendar on the site that I have been enjoying very much.

I must confess that I haven’t had a lot of time to cruise around the site, what with work and the holidays fast approaching. I’m looking forward to spending time looking and reading after the first of the year when, hopefully, things will slow down a bit. If you, gentle reader, have time to dig into it please feel free to leave a comment about your experience here on M31. K

How Have Scientists Come Up With The Size of the Known Universe?

Sloan Digital Sky Survey

Sloan Digital Sky Survey

Sloan Digital Sky Survey Galaxy Map

Well they did it with something called the Sloan Digital Sky Survey. It’s amazing. First they plotted the positions of over 900,000 galaxies in the night sky and then they measured the red-shift of each one of them to locate them in three dimensions. The way they did it is pretty ingenious and painstaking too. Even though the area mapped was a small percentage of the whole, it’s a fantastic start and very extrapolatable to the whole. The Universe has definite structure and they attribute the form of the structure to dark matter. Very fantastic matter that is no where near as weird as dark energy. They’ve discovered that the majority of the universe is comprised of dark matter.

That is astounding. It wasn’t that long ago that people thought the whole universe was comprised of the stars they could see with the unaided eye. Then the telescope was invented and our universe expanded to the limit of out best optical telescopes and still we thought we were seeing, if not all, at least the majority of what was out there. We launched Hubble and the Hubble Deep Field Survey expanded our universe once again, showing that a small, very small, part of space that appeared empty actually was crowded with galaxies, not just stars but what we had previously thought were stars were in fact whole galaxies! Now we have learned that the vast majority of what makes up our universe is there, in the area’s we’ve looked for so long and we’ve been absolutely unable to see it.

This excites me because it points to the concept that there is so much more for us to discover. And discover it we will because we are ever curious. We look up and we question. We look down and we question. We look outward and inward and we question. How amazing is that? That our universe has brought forth life capable of asking questions that have nothing to do with survival or comfort but have to do with pure knowledge. We are amazing inhabitants of an amazing universe. Never forget that. Not only are we comprised of stardust, but we are, every one of us from the most humble to the mighty, are remarkable, amazing creatures.

There have been so many cool things happening in the sky recently, or perhaps there have always been such amazing things going on and we’ve only just developed the technology to see some of them. We have always asked the questions though.

ISON Survives After A fashoion

Image Credit: 

Image Credit:  ESA/NASA/SOHO/Jhelioviewer

Image Credit:

On Thanksgiving day comet ISON grazed the sun. News at first looked grim for the 3 mile wide bit of ice and dust from the outer reaches of our solar system. The first reports were that the comet had not survived. Two telescopes did not see it emerge on the other side of the sun and it was thought that the comet had either been torn apart by the immense gravity or been vaporized by the extreme temperatures.

Then, the following day reports from other telescopes came in and it appears that the comet, or more accurately, a part of it, did survive. Check out this video from the Solar and Heilotrophic Observatory

It’s still too early to know precisely what happened and how much of the comet survived but it appears that some part of it did. Will it get as bright as some had hoped? Unlikely but still possible.

ISON Slingshots Around The Sun On Thanksgiving




Comet ISON is about to be out of view from Earth as it slingshots around the sun. The 3 mile wide chunk of primeval ice from the birth of our solar system will skim barely over the surface of the sun, just 1.1 million miles away, classifying it as a Sungrazing comet . In fact it is a large Sungrazing comet and as such is of particular interest. If the temperature doesn’t vaporize the rock and ice that make up the comet, the colossal gravity of our sun could well tear it apart.

Already astronomers think some pieces of the comet have broken off, creating wing-like structures and resulting in the brightening that has been observed in recent days. If ISON isn’t pulled into the Sun by gravity, and it’s moving pretty fast so there’s a good chance it might survive the close approach, then in December it’ll round the other side and possibly be even more spectacular than it has been.

To see Comet ISON the best thing to do is get in touch with your local amateur astronomers club or science museum. This is just the kind of thing that science museums, local observatories and astronomers clubs like to cooperate on. We drove out to a state park to get outside of the glare from the city and some very kind folks allowed us to look through the eye-piece of their gorgeous 8″ telescope that they had painstakingly set up and sighted on ISON already.

Mercury was gorgeous, ISON was amazing, we also saw Jupiter, Orion, Vega and the Pleadies. Sure we were up before sunrise and it was cold but a few mugs of hot chocolate or coffee and it was an adventure that everyone enjoyed. It’s a memory that will last a lifetime, especially since ISON has never been seen by our species before. Astronomers think this is the first time it has come into the inner solar system from the Oort cloud approximately 1 light year away and there is a good chance it’ll never be seen again by our kind. ISON has spent the last 4.5 billion years in the Oort cloud.

Even now there is uncertainty as to what will become of ISON. Will it survive Sungrazing our own star? Will it plunge into the stellar inferno? Will it survive only to be ejected from our solar system entirely? Or will it fly back out into the Oort cloud from whence it came and return again in 190 million years – 350 million years or more? Because no one knows what will happen when it slingshots around the sun, no one knows for certain what ISON’s ultimate fate is just yet.

ISON NASA Deep Impact Spacecraft

ISON NASA Deep Impact Spacecraft

Stargazing, comet watching, these are the kinds of things that families and communities can do together for very little money. Our local science museum had people on hand to talk about the comet and our solar system. Next time I’m bringing a couple dozen doughnuts to share.

Hubble Space Telescope Solves Galactic Mystery

Hubble Image of Magellanic Stream courtesy of NASA

Hubble Image of Magellanic Stream courtesy of NASA

Hubble Image of Magellanic Stream courtesy of NASA

The Hubble Space Telescope has been one of NASA’s many shining successes. The images Hubble has taken and scientists have compiled over its brief lifespan have been nothing short of breathtaking. The Hubble Space Telescope Deep Field Survey expanded our universe by lightyears upon lightyears.

Recently Hubble was turned on a puzzling feature of our Galaxy: A long ribbon of gas, called the Magellanic Stream, that reaches quite literally almost half way around our own Milky Way Galaxy.

For 40 years scientists have wondered about this feature that seemed to follow behind the Large and Small Magellanic Clouds, two dwarf galaxies that orbit our own galaxy. According to NASA:

Astronomers using NASA’s Hubble Space Telescope have solved a 40-year mystery on the origin of the Magellanic Stream, a long ribbon of gas stretching nearly halfway around our Milky Way galaxy.
The Large and Small Magellanic Clouds, two dwarf galaxies orbiting the Milky Way, are at the head of the gaseous stream. Since the stream’s discovery by radio telescopes in the early 1970s, astronomers have wondered whether the gas comes from one or both of the satellite galaxies. New Hubble observations reveal most of the gas was stripped from the Small Magellanic Cloud about 2 billion years ago, and a second region of the stream originated more recently from the Large Magellanic Cloud.
A team of astronomers, led by Andrew J. Fox of the Space Telescope Science Institute in Baltimore, Md., determined the source of the gas filament by using Hubble’s Cosmic Origins Spectrograph to measure the amount of heavy elements, such as oxygen and sulfur, at six locations along the Magellanic Stream. They observed faraway quasars, the brilliant cores of active galaxies, that emit light that passes through the stream. They detected the heavy elements from the way the elements absorb ultraviolet light.
Fox’s team found a low amount of oxygen and sulfur along most of the stream, matching the levels in the Small Magellanic Cloud about 2 billion years ago, when the gaseous ribbon is thought to have formed. In a surprising twist, the team discovered a much higher level of sulfur in a region of the stream that is closer to the Magellanic Clouds.

Also a quick video also from NASA and the Hubble Space Telescope featuring comet ISON

You can follow the Hubble Space Telescope very easily at the NASA web site. K.

NASA’s Chandra X-Ray Observatory Worth Following

Cassiopeia A courtesy of NASA's Chandra X-Ray Observatory

Cassiopeia A courtesy of NASA's Chandra X-Ray Observatory

Cassiopeia A courtesy of NASA’s Chandra X-Ray Observatory

NASA, that most wonderful, educational, altruistic of Government programs makes much of what it discovers available free on the web. This is the purest of the lofty ideals of science as a discipline and as a philosophy: That what science discovers is for the benefit of all mankind not just the enrichment of a few.

The Chandra X-Ray Observatory, which you can easily follow in Facebook describes itself thusly:

NASA’s Chandra X-ray Observatory is a telescope specially designed to detect X-ray emission from very hot regions of the Universe such as exploded stars, clusters of galaxies, and matter around black holes.
Chandra is designed to observe X-rays from high-energy regions of the Universe.
Since its launch on July 23, 1999, the Chandra X-ray Observatory has been NASA’s flagship mission for X-ray astronomy, taking its place in the fleet of “Great Observatories.”

NGC7793ChandraThey publish some of the most beautiful images of the stars and outer space that I’ve seen. They rival the Hubble Space Telescope and sometimes when I’m feeling a bit down or something I look at these gorgeous images of the universe we live in and they fill me with peace and awe. K.

Annual Perseid Meteor Shower Peaks Tonight, Aug 11

Perseid Map courtesy NASA

Perseid Map courtesy NASA

Perseid Map courtesy NASA

This map shows where, in North America, to look to see the Perseids. They seem to radiate out from the constellation Perseus.

The shooting stars we see during a meteor shower are in fact bits of rock, dust an debris falling into our atmosphere. The enormous friction caused by the high velocity of the objects and the density and composition of our atmosphere literally cause the objects to glow and burn as they enter.

The Perseids were once a part of the tail of the comet Swift-Tuttle, which orbits our sun once every 130 years. A piece of it got ripped off during an orbit and every year the Earth passes through the region of space where that debris floats in space. It is beautiful and awe inspiring to watch. I hope it clears up here so I can see some tonight.

According to NASA some 10 to 40 tons (I guess depending upon the day and the density of the material in any given part of space the Earth is passing through) fall into our atmosphere each day. Most of this is invisible to us. It takes one of the bigger showers like the Perseids or the Leonids for us to be able to see some of the meteoric entries into our atmosphere.

This is the universe happening right in our backyards here. If you have the chance, go out and spend a few minutes skywatching. some of the meteors even get bright enough to be seen through the glow of the city. K.

The Latest News for Comet ISON

Hubble's view of Comet ISON (C/2012 S1) on April 10, 2013. This image was taken in visible light. The blue false color was added to bring out details in the comet structure. Credit:NASA, ESA, J.-Y. Li (Planetary Science Institute), and the Hubble Comet ISON Imaging Science Team

Hubble's view of Comet ISON (C/2012 S1) on April 10, 2013. This image was taken in visible light. The blue false color was added to bring out details in the comet structure. Credit:NASA, ESA, J.-Y. Li (Planetary Science Institute), and the Hubble Comet ISON Imaging Science Team

Hubble’s view of Comet ISON (C/2012 S1) on April 10, 2013. This image was taken in visible light. The blue false color was added to bring out details in the comet structure. Credit:NASA, ESA, J.-Y. Li (Planetary Science Institute), and the Hubble Comet ISON Imaging Science Team

NASA’s Hubble Telescope took an amazing shot of Comet ISON in April that shows its coma against the velvety backdrop of space. The coma is already approximately 3,100 miles across (approx: 4,988.97 km). The really mind boggling thing about this is that early measurements indicate that the nucleus that is producing this enormous coma is no more than 3 or 4 miles across (4.828 to 6.437 km).

There is some speculation that it could get as bright as the full moon come late November, early December after it skims a bare 700,000 miles (1,126,540.8 km) above the surface of the sun on November 28th during the swing around before heading back out of the solar system.

For more information and to keep track look to NASA’s website.