Universe Today

Want to help your kids better understand Jupiter, and the rest of the Solar System?

See Jupiter with your own eyes
The first thing you should do is help them go out and find Jupiter with their own eyes. Jupiter is the third brightest object in the Solar System, after Venus and the Moon – when Jupiter is in the sky, you really can’t miss it. When Jupiter is really well positioned, we’ll have articles here on Universe Today about it.

It’s even better to get your hands on a pair of binoculars, but you won’t be able to see the disk of the planet, or any of its moons without a fairly powerful set of binoculars. Once you look at Jupiter through a telescope, though, it’s easy to see the disk of the planet, bands across its face, and its four largest moons.

Build a scale model of the solar system
Another great project is to build a model of the Solar System. We’ve got instructions here on Universe Today so that you draw a scale model of Sun that fits on a piece of paper, and then how many meters away to put each of the planets, and how big they should be. You can put an entire Solar System within about a kilometer of your house.

Show them what their weight would be on Jupiter
Have your children stand on a scale to see their weight, and then help them see what it would feel like if they were standing on the surface of Jupiter (of course, Jupiter doesn’t actually have a surface). Then push down on their shoulders and have the scale increase in weight. Your weight on Jupiter is 2.5 times your weight on Earth. Don’t push too hard, they’ll probably tell you it’s too much pretty quickly. The stand with them on the scale, and even that probably won’t be enough.

Draw Jupiter
Get out your crayons and try drawing Jupiter. The dark colored stripes on Jupiter are called bands, and the light colored stripes are zones, and they alternate across the surface of Jupiter. You’ll also want to include the Great Red Spot, and maybe Red Spot Jr. The smaller storms are brown or yellow, and the smallest ones are white.

Here’s a link to the project that explains how to build a model of the Solar System, and here are some images of Jupiter you can use when drawing your own version.

Kids Astronomy has more projects you can do with your kids, and an astronomer answers questions about Jupiter.

We’ve also recorded an entire show just on Jupiter for Astronomy Cast. Listen to it here, Episode 56: Jupiter, and Episode 57: Jupiter’s Moons.

Reference:
NASA

I’m lucky enough to have twin sons. They aren’t identical (one looks like me, the other looks like my husband – which is about as different as things get) but they have a lot of similarities. One of my favorite stories about having twins is the time we took the whole family out to a restaurant shortly after the twins were born. The waitress commented that our babies looked the same size, and we said, “Yes, they’re twins.” And she replied, “Oh really? How far apart in age are they?”

I used to think that waitress was a real ditz, but after seeing a press release today from Vanderbilt University, I’m wondering if the waitress was on to something, and maybe she was even an astronomer.

Astronomers recently found a very young pair of identical binary stars that have surprising differences in brightness, surface temperature and size. They also believe one of the stars formed significantly earlier than its twin. Astrophysicists have assumed that binary stars form simultaneously, and so this discovery forces theorists back to the drawing board to determine if their models can produce binaries with stars that form at different times.

The identical twins were discovered in the Orion Nebula, a well-known stellar nursery, 1,500 light years from Earth. The newly formed stars are about 1 million years old. With a full lifespan of about 50 billion years, that makes them equivalent to one-day-old human babies.

“Very young eclipsing binaries like this are the Rosetta stones that tell us about the life history of newly formed stars,” says Keivan Stassun, associate professor of astronomy at Vanderbilt University. He and Robert D. Mathieu from the University of Wisconsin-Madison headed up the project.

The astronomers calculated that these twin stars have nearly identical masses, about 41 percent that of the sun. According to current theories, mass and composition are the two factors that determine a star’s physical characteristics and dictate its entire life cycle. Because the two stars condensed from the same cloud of gas and dust they should have the same composition. And with identical mass and composition, they should be identical in every way. So the astronomers were surprised when they discovered that the twins exhibited significant differences in brightness, surface temperature and possibly size.

“The easiest way to explain these differences is if one star was formed about 500,000 years before its twin,” says Stassun. “That is equivalent to a human birth-order difference of about half of a day.”

Now, I have heard stories of twins being born several hours apart and even in different years (one late on Dec. 31, and the other early on Jan. 1) so, maybe this difference in star formation isn’t such a big deal, and it happens all the time. However, further study is needed.

But this new discovery may cause astronomers to readjust their estimates of the masses and ages of thousands of young stars less than a few million years old, as current estimates are based on models that presumed binary stars formed simultaneously.

Just like having twins causes you to readjust your entire life. But it’s a good readjustment.

Original News Source: Vanderbilt University (this link includes a nice multimedia presentation about the discovery)

Worried about how you’re going to feed your black hole once it grows up and gets big? Have no fear. New data from the Chandra X-ray Observatory indicates that even the biggest black holes may feed just like the smallest ones. Using new observations and a detailed theoretical model, a research team compared the properties of the black hole of the spiral galaxy M81 with those of smaller, stellar mass black holes. The results show that big or little, black holes appear to eat similarly to each other, and produce a similar distribution of X-rays, optical and radio light. This discovery supports the implication of Einstein’s relativity theory that black holes of all sizes have similar properties.

M81 is about 12 million light years from Earth. In the center of M81 is a black hole that is about 70 million times more massive than the Sun, and generates energy and radiation as it pulls gas in the central region of the galaxy inwards at high speed.

In contrast, so-called stellar mass black holes, which have about 10 times more mass than the Sun, have a different source of food. These smaller black holes acquire new material by pulling gas from an orbiting companion star. Because the bigger and smaller black holes are found in different environments with different sources of material to feed from, a question has remained about whether they feed in the same way.

“When we look at the data, it turns out that our model works just as well for the giant black hole in M81 as it does for the smaller guys,” said Michael Nowak, from the Massachusetts Institute of Technology. “Everything around this huge black hole looks just the same except it’s almost 10 million times bigger.”

One of the implications of Einstein’s theory of General Relativity is that black holes are simple objects and only their masses and spins determine their effect on space-time. The latest research indicates that this simplicity manifests itself in spite of complicated environmental effects.

The model that Markoff and her colleagues used to study the black holes includes a faint disk of material spinning around the black hole. This structure would mainly produce X-rays and optical light. A region of hot gas around the black hole would be seen largely in ultraviolet and X-ray light. A large contribution to both the radio and X-ray light comes from jets generated by the black hole. Multi-wavelength data is needed to disentangle these overlapping sources of light.

Among actively feeding black holes the one in M81 is one of the dimmest, presumably because it is “underfed”. It is, however, one of the brightest as seen from Earth because of its relative proximity, allowing high quality observations to be made.

“It seems like the underfed black holes are the simplest in practice, perhaps because we can see closer to the black hole,” said Andrew Young of the University of Bristol in England. “They don’t seem to care too much where they get their food from.”
This work should be useful for predicting the properties of a third, unconfirmed class called intermediate mass black holes, with masses lying between those of stellar and supermassive black holes. Some possible members of this class have been identified, but the evidence is controversial, so specific predictions for the properties of these black holes should be very helpful.

In addition to Chandra, three radio arrays (the Giant Meterwave Radio Telescope, the Very Large Array and the Very Long Baseline Array), two millimeter telescopes (the Plateau de Bure Interferometer and the Submillimeter Array), and Lick Observatory in the optical were used to monitor M81.
The results of this study will appear in an upcoming issue of The Astrophysical Journal.

News Source: NASA’s Chandra Website