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Bliss…

What’s Up For August 2018?

The summer Perseids are here! 

The Perseid meteor shower is the best of the year! It peaks on a Moonless summer night from 4 p.m. EST on August 12 until 4 a.m. EST on August 13.

Because the new Moon falls near the peak night, the days before and after the peak will also provide nice, dark skies. Your best window of observation is from a few hours after twilight until dawn, on the days surrounding the peak.

Unlike most meteor showers, which have a short peak of high meteor rates, the Perseids have a very broad peak, as Earth takes more than three weeks to plow through the wide trail of cometary dust from comet Swift-Tuttle.

The Perseids appear to radiate from the constellation Perseus, visible in the northern sky soon after sunset this time of year. Observers in mid-northern latitudes will have the best views.

You should be able to see some meteors from July 17 to August 24, with the rates increasing during the weeks before August 12 and decreasing after August 13.

Observers should be able to see between 60 and 70 per hour at the peak. Remember, you don’t have to look directly at the constellation to see them. You can look anywhere you want to-even directly overhead.

Meteor showers like the Perseids are caused by streams of meteoroids hitting Earth’s atmosphere. The particles were once part of their parent comet-or, in some cases, from an asteroid.

The parade of planets Venus, Jupiter, Saturn and Mars–and the Milky Way continue to grace the evening sky, keeping you and the mosquitoes company while you hunt for meteors.

Watch the full What’s Up for August Video: 

There are so many sights to see in the sky. To stay informed, subscribe to our What’s Up video series on Facebook.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

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Images of Saturn, Tethys, and Mimas taken by Cassini on July 16 2005.

Credit: NASA/JPL-Caltech/SSI/CICLOPS/Kevin M. Gill

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By jayeffex

What is a Wormhole?

Wormholes were first theorized in 1916, though that wasn’t what they were called at the time. While reviewing another physicist’s solution to the equations in Albert Einstein’s theory of general relativity, Austrian physicist Ludwig Flamm realized another solution was possible. He described a “white hole,” a theoretical time reversal of a black hole. Entrances to both black and white holes could be connected by a space-time conduit.

In 1935, Einstein and physicist Nathan Rosen used the theory of general relativity to elaborate on the idea, proposing the existence of “bridges” through space-time. These bridges connect two different points in space-time, theoretically creating a shortcut that could reduce travel time and distance. The shortcuts came to be called Einstein-Rosen bridges, or wormholes.

Certain solutions of general relativity allow for the existence of wormholes where the mouth of each is a black hole. However, a naturally occurring black hole, formed by the collapse of a dying star, does not by itself create a wormhole.

Wormholes are consistent with the general theory of relativity, but whether wormholes actually exist remains to be seen.

A wormhole could connect extremely long distances such as a billion light years or more, short distances such as a few meters, different universes, or different points in time

For a simplified notion of a wormhole, space can be visualized as a two-dimensional (2D) surface. In this case, a wormhole would appear as a hole in that surface, lead into a 3D tube (the inside surface of a cylinder), then re-emerge at another location on the 2D surface with a hole similar to the entrance. An actual wormhole would be analogous to this, but with the spatial dimensions raised by one. For example, instead of circular holes on a 2D plane, the entry and exit points could be visualized as spheres in 3D space.

Science fiction is filled with tales of traveling through wormholes. But the reality of such travel is more complicated, and not just because we’ve yet to spot one.

The first problem is size. Primordial wormholes are predicted to exist on microscopic levels, about 10–33 centimeters. However, as the universe expands, it is possible that some may have been stretched to larger sizes.

Another problem comes from stability. The predicted Einstein-Rosen wormholes would be useless for travel because they collapse quickly.

“You would need some very exotic type of matter in order to stabilize a wormhole,” said Hsu, “and it’s not clear whether such matter exists in the universe.”

But more recent research found that a wormhole containing “exotic” matter could stay open and unchanging for longer periods of time.

Exotic matter, which should not be confused with dark matter or antimatter, contains negative energy density and a large negative pressure. Such matter has only been seen in the behavior of certain vacuum states as part of quantum field theory.

If a wormhole contained sufficient exotic matter, whether naturally occurring or artificially added, it could theoretically be used as a method of sending information or travelers through space. Unfortunately, human journeys through the space tunnels may be challenging.

Wormholes may not only connect two separate regions within the universe, they could also connect two different universes. Similarly, some scientists have conjectured that if one mouth of a wormhole is moved in a specific manner, it could allow for time travel.

Although adding exotic matter to a wormhole might stabilize it to the point that human passengers could travel safely through it, there is still the possibility that the addition of “regular” matter would be sufficient to destabilize the portal.

Today’s technology is insufficient to enlarge or stabilize wormholes, even if they could be found. However, scientists continue to explore the concept as a method of space travel with the hope that technology will eventually be able to utilize them.

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Halloween hike/drive

October 31st, 2018

Front Royal, VA

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