Approaching Comet As Big As The Full Moon


Work ground to a halt this afternoon when an alert from http://spaceweather.com/ declared, “A Comet As Big As the Full Moon” was fast approaching Earth. I read on…

On Dec. 16th, Comet 46P/Wirtanen will approach Earth less than 11.5 million km away–making it one of the 10 closest-approaching comets of the Space Age. It’s a small comet, with a nucleus barely 1 km wide, but such proximity makes even a small things appear large. The comet’s gaseous atmosphere is now as wide as a full Moon. Mike Broussard of Perry, Louisiana, photographed the comet on Dec. 2nd and inserted the Moon for scale:”

Logically, a full moon size comet wasn’t about to graze Earth. Kudos for making me click, but the key phrase is “proximity makes even a small thing look large”. 46P is a Jupiter-family comet, one of over 400 identified comets with orbital periods less than 20 years, whose farthest point from the Sun is near the orbit of Jupiter. From https://www.space.com/42575-see-comet-64p-wirtanen-earth-flyby-december-2018.html ….

Jupiter-family comets will occasionally have their orbits perturbed when they make a close approach to Jupiter because its strong gravitational field can alter — sometimes quite significantly — a comet’s path through space.

In the case of 46P/Wirtanen, it underwent two such interactions with Jupiter — in April 1972 and February 1984 — that pushed its orbit about 50 million miles closer to the sun as well as very near to the orbit of Earth. With its current orbital period of 5.4 years, it has been alternating between evening-sky and morning-sky returns. But the evening-sky returns have been getting progressively more favorable.

Comet 46P Wirtanen
Taken by Gerald Rhemann on December 3, 2018 @ Farm Tivoli, Namibia, SW – Africa

Bottom line – On December 16, 2018 at 8:06 a.m. EST, 46P/Wirtanen will pass 11,586,350 kilometers from Earth, making 46P one of the top ten close approaches since 1950 and top twenty since the 9th century A.D.

 

Comet 46P/Wirtanen will be closest to Earth on Dec. 16, 2018. Look for it above the eastern horizon after dusk all month long! It will be bright enough to see with the naked eye, and will look even more spectacular with binoculars and telescopes.

Credit: SkySafari App

 

 

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Violet Road


Last week astro-photographer Adrien Mauduit filmed the first ever live concert under the Northern Lights. From the aurora borealis observatory in Senja, Norway – ponder Norwegian band Violet Road performing “Keep on Running” under aurora’s light….

Follow Adrien Mauduit at – https://www.youtube.com/channel/UCC0CLzCpM6nuLSAi1JNBjkA

Jovian Close Encounter


October 29, 2018  7,000 kilometers above the cloud tops of Jupiter, NASA orbiter Juno captured this image –

Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstädt/Seán Doran

https://earthsky.org/space/juno-spacecraft-image-nov-2018-eichstadt-doran?utm_source=EarthSky+News&utm_campaign=31140f2af9-EMAIL_CAMPAIGN_2018_02_02_COPY_01&utm_medium=email&utm_term=0_c643945d79-31140f2af9-393970565

Citizen scientists Gerald Eichstädt and Seán Doran created this color-enhanced image using data from the spacecraft’s JunoCam imager. JunoCam’s raw images are available for the public to peruse and to process into image products here.

Geomagnetic Storm


It began with a routine check of space weather before bed. I say routine because it used to be daily ritual until a few months ago when work took siege of every waking moment. Not so long ago I would have been all over a geomagnetic storm, auroras are my thing and I miss them. SpaceWeather http://spaceweather.com/ told of “the next geomagnetic storm”, Earth’s exit from one solar stream and anticipated arrival of another on November 18. Oh man, what solar stream? Then I remembered Adrien Mauduit, newly discovered astro-photographer and visionary whose efforts warm my heart.

Sure enough, Mauduit not only knew of last weekend’s solar storm, he captured its ethereal beauty in HD.

Adrien Mauduit wrote “If you missed the show last night, here’s a recap of what happened from the Aurora observatory on Senja island, Norway. “

Harvard Research Ignites Alien Probe Frenzy


In October 2017 astronomers at Pan-STARRS 1 telescope in Hawaii, spotted a mysterious fast moving cigar shaped object. They named it Oumuamua, Hawaiian for “messenger from afar arriving first” or “scout”.

Image result for oumuamua

Artist’s impression of the first interstellar asteroid/comet, “Oumuamua”. This unique object was discovered on 19 October 2017 by the Pan-STARRS 1 telescope in Hawaii. Credit: ESO/M. Kornmesser

For 3 months the roughly 400 metre long object blazed through our inner solar system at a staggering 26 kilometres per second. Mystified astronomers didn’t know what to make of Oumuamua, Without a debris trail it couldn’t be a comet, void of discernible trajectory it wasn’t an asteroid. Enter the Harvard Smithsonian Center for Astrophysics, in a new paper submitted to the Astrophysical Journal Letters, researchers dangle the possibility Oumuamua is a “lightsail of artificial origin”.

Oumuamua may be a fully operational probe sent intentionally to Earth vicinity by an alien civilization,” the paper’s authors wrote.

The object’s “excess acceleration” when it traveled through our solar system and its peculiar trajectory distinguishes it from comets and asteroids, the researchers explained.

For example, the object’s movement is not determined by the gravitational pull of the sun or planets, as is the case with asteroids. Scientists have also been unable to concretely identify it as a comet because it lacks a tail or “coma” around it.

To explain its movement, the report’s authors, Abraham Loeb, a professor and chair of astronomy, and Shmuel Bialy, a postdoctoral fellow, argue that Oumuamua’s non-gravitational acceleration may be explained by solar radiation pressure.”

Solar radiation pressure is key to Harvard’s lightsail hypothesis.

If radiation pressure is the accelerating force, then Oumuamua represents a new class of thin interstellar material, either produced naturally, through a yet unknown process… or of an artificial origin,” the authors wrote.

If the interstellar object is as thin as astronomers estimate it to be, Loeb and Bialy suggest it could be a light sail, which is conceived as able to harness light or solar energy from the sun to propel a spacecraft.”

If Oumuamua is a lightsail floating in interstellar space, it could have been ejected from a planetary system as “space debris” from equipment that is no longer operational.

“This would account for the various anomalies of Oumuamua, such as the unusual geometry inferred from its light-curve, its low thermal emission, suggesting high reflectivity, and its deviation from a Keplerian orbit without any sign of a cometary tail or spin-up torques,” the paper states.

Although it’s “extremely thin,” the researchers said the object could survive interstellar travel over galactic distances and withstand collisions with gas and dust grains.

Bold, italic content above credited to Jackie Dunham,  CTV linked below –

https://www.ctvnews.ca/sci-tech/mysterious-cigar-shaped-interstellar-object-may-be-alien-spacecraft-harvard-researchers-1.4165513

In a world of televised ancient alien theory, blog fueled extraterrestrial existence and self proclaimed definitive authority on cosmic visitors, it’s tempting to jump on the Harvard said so bandwagon. Not so fast people! Settle down, look at the facts and understand Harvard isn’t declaring Oumuamua an alien probe. It is saying there’s a lot we don’t understand and wouldn’t it be cool if this were the case. Either way, we’re talking about it and that’s good enough for me.