Abrabanel: Musings on the Jewish condition

An earth-shattering revolution in physics, explained for the rest of us:

Scientists are studying the signatures of Earth from space to figure out what a life-sustaining planet would look like from afar.

In essence, if we want to find life on alien planets, we have to study a planet known to host life to determine what clues to look for, scientists say.

The researchers are using the European Space Agency’s Venus Express satellite, in orbit around our neighbor planet, to study Earth from afar, where it appears smaller than a pixel in the spacecraft’s cameras, with no surface details visible. …

So far, the project has learned that tracking down signs of life and livability is not as easy as it sounds.

“We see water and molecular oxygen in Earth’s atmosphere, but Venus also shows these signatures,” Piccioni said. “So looking at these molecules is not enough.”

A more subtle signal that could differentiate the two types of worlds is the so-called red edge – the infrared signal caused by photosynthetic life. “Green plants are bright in the near infrared,” Grinspoon said.

The Venus Express team is only beginning to analyze the Earth data to see if our planet’s red edge is detectable from a distance. …

The study could prove vital in scientists’ ongoing quest to learn more about the ever-growing catalog of distant worlds we’ve found in the galaxy.

It’s those newly discovered planets that makes the discovery so potentially promising:

Since 1995, astronomers have discovered more than 300 extrasolar planets. And two new satellite missions — the ESA/French Space Agency COROT satellite currently in orbit and NASA’s Kepler Mission spacecraft set to launch in March 2009 — bring us closer to the holy grail of exoplanet research: finding Earth-sized worlds around other stars.

So beautiful it looks like a painting.

We’re on vacation, so things are coming slower this past ten days or so. We’ll be back in force after Rosh Hashanah. In the meantime, things you really shouldn’t miss if you read blogs like this one:

• Bill Clinton explains multiple times that he won’t campaign on the Jewish High Holidays. Yeah, we’re not sure what this means either.
• Yossi Melman of Ha’aretz argues that Russia’s anger at the West is bringing about the collapse of the sanctions regime against Iran. “Russia is strengthening the Iranian regime and signaling to it that the basic, though superficial, international consensus against it has ceased to exist.” Yossi Melman is a clever old hand in this business. His say-so is more significant than some New York Times foreign affairs columnist.
• A great review of an excellent new book on Maimonides.
• Oh, and the universe is, as always, more complicated than we once believed. Scientists have found an unexplained “drift” or “flow” of immense galactic clusters in a single direction, as opposed to motion in all directions as space itself expands. As The Daily Galaxy explains, “A black hole can’t explain the observations – objects would accelerate into the hole, while the NASA scientists see constant motion over a vast expanse of a billion light-years. You have no idea how big that is. This is giant on a scale where it’s not just that we can’t see what’s doing it; it’s that the entire makeup of the universe as we understand it can’t be right if this is happening.”

NASA is going after space weather, launching a new satellite telescope that can see the magnetic fields down in the bowels of the solar atmosphere:

Researchers call it “the transition region.” It is a place in the sun’s atmosphere, about 5000 km above the stellar surface, where magnetic fields overwhelm the pressure of matter and seize control of the sun’s gases. It’s where solar flares explode, where coronal mass ejections begin their journey to Earth, where the solar wind is mysteriously accelerated to a million mph.

It is, in short, the birthplace of space weather.

You’ve probably already seen this if you’re into cosmology. But here it is anyway, the first actual observations of the envisaged “dark matter,” an unseen source of mass that accounts for most of the gravitational pull in the universe. Unseen, that is, except for that gravitational effect.

Now the unbelievably clever researchers who are piecing together our model of the universe have managed to track the movement of a gravitational field the size of several galaxies while the actual galaxies slowed down. In a collision of galactic clusters, they spotted the slow-down of the detectable matter as it crashed into more matter, while the “dark matter” – and its gravitational pull – kept going.

The Milky Way’s stellar halo apparently looks not like a slowly dissipating globe of stars, but more like “a jumble of pasta” in which stellar strands stretch outward in the return paths of satellite galaxies that once merged into ours, according to new measurements of groups of stars found to be moving in tandem through the galactic halo.

What does this mean? It means we get to see gorgeous hypothetical models like this one:

Some stunning pics from NASA this week.

To the right, a thin sheen of dew covers the dirt and rocks of Mars as the sun begins to rise over the horizon. It’s an intimate closeup of our closest fellow planet. No matter how many times we hear scientists insist that the Earth’s ecology is probably not utterly unique in the universe, it still puts a smile on our face to see something so familiar…elsewhere.

The picture was taken August 14th by Phoenix.

And to the left, two entire galaxies are caught in the middle of a collision (or, rather, merger) that will last hundreds of millions of years. According to NASA’s caption, “Although it is likely that no stars in the two galaxies will directly collide, the gas, dust, and ambient magnetic fields do interact directly.”

The picture comes from the always breathtaking Hubble.

Hat tip: Digg.