The name is terribly mundane, but the consequences of the close pass of asteroid 2014 JO25 last week are anything but. This peanut-shaped, 1400-yards, asteroid whizzed past Earth at a distance of about 1 million miles. At 4 time the Earth-Moon distance, that seems pretty safe, but in astronomy sizes that is a buzz call.
“Good news: Wednesday was the closest this asteroid has been in 400 years, and it won’t get this close again for at least 500 years. It’s not going to hit Earth, and if it were, we’d know it by now.
Somewhat disconcerting news: When the radar at Arecibo Observatory in Puerto Rico spotted it, astronomers realized the space rock was larger than they had thought. Today’s estimate is about 0.8 miles wide.
Let us, for a moment, consider a scenario in which a 0.8-mile-wide asteroid strikes Earth. First, the magic number for total apocalypse is 60 miles. That’s how big an asteroid would need to be to wipe out human life. At six miles wide, even the asteroid that led to dinosaur extinction was much smaller than the Earth-obliterating scenario.
When physics tells me an asteroid this large would release 1031 Joules of kinetic energy, I take note. That’s how much energy the sun releases in a day. Think about that for a minute. But don’t dwell! Breathe easy.
Luckily, there’s nothing that large orbiting in our neighborhood. Instead, we’re plagued by articles like this that pop up every other month when little space rocks pass our planet 1 million miles away.”
Aurora on Earth are caused by particles from the Sun interacting with our planet’s protective magnetic field. Without that magnetic field on Earth, we would not be here. All life is entirely dependent on the shielding that our magnetic field provides. So if we are to search for life elsewhere, one good way to separate out those planets that may harbor life from those that do not, will be to search for Aurora. Except we’re not at the stage in our technology where we can image planets around other stars well enough to see aurora. So we have to find another way.
Luckily, the aurora also produces radio waves. So instead of watching, we can listen.
ET is not phoning home, but we are hearing the potential for life in our solar system
The search for life around other stars is essentially a search for a habitable zone – the area around a star where the distance is warm enough to sustain liquid water on the surface, but cold enough such that the water does not boil away or escape.
This definition of habitable zone now has to change to take into account the star itself. New research shows that winds coming off Red Giant stars can strip the planet of Oxygen. No Oxygen, no life. This means that our nearest confirmed Earth-sized exoplanet, around Proxima Centauri and only 4 light-years away, is not a good spot to go look for neighbors.
“If we want to find an exoplanet that can develop and sustain life, we must figure out which stars make the best parents,” said Vladimir Airapetian, lead author of the paper and a solar scientist at NASA’s Goddard Space Flight Center. “We’re coming closer to understanding what kind of parent stars we need.”
The probability of intelligent life beyond Earth is very high. Its almost certain. But as space is big, the probability of any two intelligent sets of life on different planets communicating is pretty low.
However, simple life forms may be everywhere. Provide 3 things – water, heat and some nutrition – and life seems to get going pretty quick. One of the best spots for these three things may be Enceladus. This moon of Saturn was long considered a dead world. But new data is showing just how alive it might actually be.
“New findings from NASA’s Hubble Space Telescope show suspected water plumes erupting from Jupiter’s icy moon Europa. These observations bolster earlier Hubble work suggesting that Europa is venting water vapor. The plumes are estimated to rise about 125 miles before, presumably, raining material back down onto Europa’s surface. This is exciting because Europa is a plausible place for life to have developed beyond the Earth. If the venting plumes originate in a subsurface ocean, they could act as an elevator to bring deep-sea life above Europa’s surface, where it could be sampled by visiting spacecraft. This offers a convenient way to access the chemistry of that ocean without drilling through miles of ice”
Find a weekend, pack a tent, hotdogs and smores, and stay at the City of Rocks, NM. The dark skies in New Mexico are one of our greatest assets . 1 hour from Las Cruces, 30 minutes from Silver City, and you might as well be alone in this universe. Go see the beauty of the Milky Way with your own eyes.
The faint young Sun paradox was originally posed by Carl Sagan. Primitive life existed on Earth 4 billion years ago. But back then the Sun was much fainter, so too cold to supply the heat for life on Earth. So we need a big greenhouse effect to warm things up. The trouble with that solution is that it requires 300 time more carbon dioxide than we have today, which would make the Earth to acidic to allow life to happen. This new research poses a new answer – large frequent solar flares from an angry young Sun result in Nitrous Oxide in the Earth’s early atmosphere. This gas is a much more efficient greenhouse gas, so it only requires a small amount to supply the extra heat. As a bonus, this process that creates the Nitrous Oxide also creates abundant hydrocarbons required to cook up life.
This raises the possibility of life being much more abundant in the Universe than we had thought previously. If young stars can produce flares like our Sun, then the habitable zone (the not-too-far, yet not-to-close distance from the star) is much, much larger and exists for a much, much longer time than anyone has considered.
Now we knew that planets had to have a formation period. We’ve even seen some titillating hints of planets forming around the time of planet formation. But now we’ve caught them in the act. For the first time, researchers have photographed the birth of a distant planet. Of course planets take several millions years to form, so we can only ever capture stills, but we can use a simulation in this video.
We know of about 2,000 exoplanets, but we’ve only imaged about a dozen, and all of them well beyond their baby phase. This new data, published in the journal Nature this week, provides our first real peek at the birth phase. The LkCa15 system was observed using Arizona’s Large Binocular Telescope, the world’s largest telescope, and the University of Arizona’s Magellan Telescope, found in Chile. The Magellan Telescope has a special adaptive optics system that was able to pick up the planet’s “hydrogen alpha” light — a specific red wavelength of light that stars and planets emit as they grow. These cosmic objects get really hot when they form, causing their hydrogen components to glow this deep red that can be observed from Earth.
This embryonic exoplanet orbits a young star called LkCa15, only about 450 light years from Earth. Surrounding LkCa15 is a huge, protoplanetary disk — a rotating saucer of dense gas that typically encompasses young stars. Within these disks planets form when some of the materials coalesce into larger objects. This creates gaps in the dust cloud where the new planets then reside. The protoplanetary disk around LkCa15 is unique – it contains an exceptionally large gap.
“It’s like a big doughnut,” said study author Kate Follette. “This system is special because it’s one of a handful of disks that has a solar-system size gap in it. And one of the ways to create that gap is to have planets forming in there.” She was able to separate the hydrogen alpha light coming from the star, to get the image of the emerging exoplanet. But, as always we couldn’t see everything — and they think there may be still more planets forming while we watch.