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Tue, 19 Nov 2019
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Comet

Incoming! ANOTHER asteroid - discovered just today - to make fly-by this week

Asteroid
© Pixabay
Earth is soon set for another close shave with a hurtling space rock as an 111-foot asteroid is poised to skim past our planet on its closest approach for 115 years.

First spotted by astronomers only earlier this week, the asteroid dubbed 2019 TA7 is set to fly by Earth at a speed of over 22,500 miles per hour at 6:53pm ET on Monday, data from NASA's Jet Propulsion Laboratory (JPL) reveals.

The new celestial visitor is estimated to measure up to 111 feet in diameter and is among a group of recently discovered asteroids that have been traveling close to Earth in recent days.

Comment: See also: Asteroid swarm: NASA detects 16 space rocks hurtling towards Earth this week


Fireball

Meteor fireball lights up sky across California

Fireball over California
© Twitter/Courtesy of @AardwolfEssex
California residents took to social media Monday night to report a glowing fireball across the night sky over multiple cities including Sacramento, Lynwood and San Diego.

One social media user caught a video of the fireball shooting across the sky while he was driving. (See below)

​Although unclear, the object appears to fit the description of a fireball, which is a meteor that burns as brightly as the planet Venus in the morning or evening sky, according to the American Meteor Society.

According to several reports, the annual Draconid meteor shower is expected to generate around eight shooting stars every hour starting Tuesday.

Comet 2

Cyanide gas found in interstellar object 2I/Borisov

Comet 2I/Borisov
© Universe Today
Comet 2I/Borisov.
When the mysterious object known as 'Oumuamua passed Earth in October of 2017, astronomers rejoiced. In addition to being the first interstellar object detected in our Solar System, but its arrival opened our eyes to how often such events take place. Since asteroids and comets are believed to be material left over from the formation of a planetary system, it also presented an opportunity to study extrasolar systems.

Unfortunately, 'Oumuamua left our Solar System before any such studies could be conducted. Luckily, the detection of comet C/2019 Q4 (Borisov) this summer provided renewed opportunities to study material left by outgassing. Using data gathered by the William Herschel Telescope (WHT), an international team of astronomers found that 2I/Borisov contains cyanide. But as Douglas Adams would famously say, "Don't Panic!"

The study, which recently appeared in The Astrophysical Journal Letters, was led by Prof. Alan Fitzsimmons of the Astrophysics Research Centre at Queen's University Belfast. He was joined by members of the European Southern Observatory (ESO), the Institute for Astronomy, the STAR Institute, the ESA's NEO Coordination Centre, the National Institute for Astrophysics (INAF), and multiple universities.

Info

New evidence sheds light on Younger Dryas impact hypothesis

Comet
© Shutterstock
Just less than 13,000 years ago, the climate cooled for a short while in many parts of the world, especially in the northern hemisphere. We know this because of what has been found in ice cores drilled in Greenland, as well as from oceans around the world.

Grains of pollen from various plants can also tell us about this cooler period, which people who study climate prehistory call the Younger Dryas and which interrupted a warming trend after the last Ice Age. The term gets its name from a wildflower, Dryas octopetala. It can tolerate cold conditions and was common in parts of Europe 12,800 years ago. At about this time a number of animals became extinct. These included mammoths in Europe, large bison in North America, and giant sloths in South America.

The cause of this cooling event has been debated a great deal. One possibility, for instance, is that it relates to changes in oceanic circulation systems. In 2007 Richard Firestone and other American scientists presented a new hypothesis: that the cause was a cosmic impact like an asteroid or comet. The impact could have injected a lot of dust into the air, which might have reduced the amount of sunlight getting through the earth's atmosphere. This might have affected plant growth and animals in the food chain.

Research we have just had published sheds new light on this Younger Dryas Impact Hypothesis. We focus on what platinum can tell us about it.

Comet 2

Hunting asteroids: NASA's Planetary Defense budget grew 4000% in 10 years

asteroid earth
© Photo: Science Photo Library / ANDRZEJ WOJCICKI / Getty Images
It wasn't the arguments that changed, it was the politics.
In 2005, Congress passed a bill requiring NASA to find and track at least 90% of all near-Earth objects (NEOs) 140 meters or larger by 2020. It was a significant step toward protecting the planet from potential asteroid impacts, but it had a major flaw: Congress neglected to specify funding for the new mandate. As a consequence, NASA's NEO survey effort was sidelined for years; as of January 2019, only 40% of the total estimated population of hazardous asteroids 140 meters and larger had been found. Meeting the 2020 mandate is now impossible.

For five years after the 2005 law, NEO survey efforts at NASA limped along with an annual budget of less than $4 million per year — roughly 0.02% of the space agency's total expenditures and less than the travel budget for employees at NASA headquarters. This money supported observation time on ground-based telescopes around the world — an important but ultimately inadequate method for detecting the extremely faint signatures of near-Earth objects.

Comment: As noted in Earth enters densest stream of deadly Taurid meteor cluster this June:
[...] scientists have identified more than 90 percent of the objects large enough to cause a global-scale disaster.

But moving down the size scale, the census is far spottier. Only about 30 percent of medium-size objects - 140 meters (460 feet) in diameter or larger - have been spotted. And she said only about 1 percent of objects have been found that are the size of the Tunguska impactor, which was about 40 meters (130 feet) in diameter. She said she welcomed the idea of a special effort to look for objects during the Taurid swarm in June.
And if something even as small as the Tunguska asteroid struck over a major city it would cause mass mortality; the situation could be particularly dire if it was part of a swarm.

For more on the current threat, see: And for an idea on the previous cataclysms humanity has endured: Also check out SOTT radio's:


Comet 2

Two sightings in two years suggest there could be lots more interstellar comets

Interstellar Comets
© VW PICS/UNIVERSAL IMAGES GROUP VIA GETTY IMAGES
It’s possible that other solar systems are flinging comets into interstellar space, and we might be able to see them in the next few years as technology improves.
For the second time in two years, astronomers have spotted an interstellar interloper heading into our Solar System.

The first, dubbed 'Oumuamua, was spotted on 19 October 2017.

This one, named 2I/Borisov, was discovered on 30 August 2019 by amateur astronomer Gennady Borisov of Nauchnij, Crimea, using a home-built 65-centimeter telescope.

It was initially thought to be an ordinary comet, says Davide Farnocchia of NASA's Center for Near-Earth Object Studies, Pasadena, California.

But a week of observations by amateur and professional astronomers revealed that it was on an orbit that must have originated outside the Solar System and is now in the process of slingshotting around the Sun before heading back into interstellar space. (The "2I" in its name means it is "interstellar object number 2.")

Already, it is proving to be quite different from its predecessor. To begin with, it's much larger. 'Oumuamua (now officially called 1I/'Oumuamua) was a cigar-shaped object, only 800 meters long. 2I/Borisov is probably several kilometers in diameter.

Comet 2

Comet 67P surprises scientists with 'bright outbursts', collapsing cliffs and rolling boulders during Rosetta mission

comet 67P/Churyumov–Gerasimenko
© Rosetta/NASA
Bouncing boulder on comet 67P/Churyumov–Gerasimenko
It seems that comet 67P/Churyumov-Gerasimenko is not the stoic, unchanging Solar System traveller that it might seem to be. Scientists working through the vast warehouse of images from the Rosetta spacecraft have discovered there's lots going on on 67P. Among the activity are collapsing cliffs and bouncing boulders.

Rosetta spent almost two years at 67P, ending its mission with a hard landing on the comet's surface. During the spacecraft's journey and its two years at the comet, it captured almost 100,000 images. About 3/4 of them are from OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) and the rest are from the NAVCAM. (You can enjoy archives of its images here.)

These images are all being analyzed by scientists, and part of that analysis involves images from during and after perihelion. Perihelion is when an object is closest to the Sun, and scientists expect to see the most changes on the comet during that time. By comparing perihelion images with those following perihelion, they hope to gain a better understanding of how the comet evolves.

Comment: In Did Earth 'Steal' Martian Water? Pierre Lescaudron provides insight into why these events on Comet 67P occurred, particularly as it approached the Sun:
Interplanetary Electric Discharge

The Electric Universe theory, as described in our book Earth Changes and the Human Cosmic Connection, shows how celestial bodies (planets, stars, moons, comets, etc) are electrically charged. In addition, such bodies are surrounded by a sort of "insulation bubble" (Double Layer).

When two astronomical bodies, like two planets, get close enough, an electric discharge forms from the most negative planet to the most positive one, in order to re-balance the electric charge of the two planets. Electric discharges between celestial bodies have been observed several times.
See also: And check out SOTT radio's:


Blue Planet

Did Earth 'Steal' Martian Water?

Mars earth plasma discharge
While finalizing the writing of the article titled "Of Flash Frozen Mammoths and Cosmic Catastrophes", I encountered an unexpected anomaly.

The time of the demise of the mammoths is also known as the Younger Dryas, a period of global cooling that lasted from 12,900 to 11,700 years ago (10,900 B.C. to 9,700 B.C.) during which surface temperatures dropped by approximately 7°C.

In theory, such a severe cooling should increase the volume of polar ice and, as a result, reduce sea level. However, during the Younger Dryas, sea levels rose 17 meters over more than a millennium, as illustrated by the graph below.
Sea level VS global temperature (20000BP-Now)

Sea level VS global temperature (20000BP-Now)
If the sea level rose while ice caps were building up, it's possible that the source of the water was external. But where could this water have come from?

Coincidentally or not, most of Mars' Northern hemisphere was once covered with water, and this ocean has mysteriously disappeared. So where did the Martian water go?

Info

Another possible interstellar comet headed our way in July 2020

Astronomers have discovered a potentially interstellar comet — the second after 'Oumuamua — and it's approaching the Sun, with a perihelion in mid-2020.
Oumuamua
© Universe Today
First there was 'Oumuamua. Now we might be in store for another interstellar flyby, this time by the recently discovered comet A/2019 Q1. Gennady Borisov captured the object on August 30, 2019, at the Crimean Astrophysical Observatory when it was about 5.5 astronomical units (a.u.) from the Sun. Unlike 'Oumuamua, which was discovered well after perihelion, the new comet is approaching the plane of the solar system and will reach perihelion on July 24, 2020 at a distance of 4.96 a.u., about the distance between Jupiter and the Sun.

But it's still early. Don't be surprised if these dates change as more observations come in.

What sets A/2019 Q1 apart from nearly every other comet is the eccentricity of its orbit. Eccentricity measures how much an orbit deviates from a perfect circle, which has an eccentricity of 0. Elliptical orbits, typical of planets, asteroids and comets, have eccentricities between 0 and 1. Parabolas are equal to 1, and an eccentricity greater than 1 indicates a hyperbolic orbit.
Object Orbit
© Stamcose / CC BY-SA 4.0 with additions by the author
How flat an object's orbit is called its eccentricity. An object on a hyperbolic orbit is likely from beyond the solar system.

Fireball

Asteroid changes color and sprouts comet-like tail

Asteroid 6478 Gault
© NASA, ESA, K. Meech and J. Kleyna, O. Hainaut
The asteroid 6478 Gault is seen with the NASA/ESA Hubble Space Telescope, showing two narrow, comet-like tails of debris that tell us that the asteroid is slowly undergoing self-destruction. The bright streaks surrounding the asteroid are background stars. The Gault asteroid is located between the orbits of Mars and Jupiter.
Last December, scientists discovered an "active" asteroid within the asteroid belt, sandwiched between the orbits of Mars and Jupiter. The space rock, designated by astronomers as 6478 Gault, appeared to be leaving two trails of dust in its wake — active behavior that is associated with comets but rarely seen in asteroids.

While astronomers are still puzzling over the cause of Gault's comet-like activity, an MIT-led team now reports that it has caught the asteroid in the act of changing color, in the near-infrared spectrum, from red to blue. It is the first time scientists have observed a color-shifting asteroid, in real-time.

"That was a very big surprise," says Michael Marsset, a postdoc in MIT's Department of Earth, Atmospheric and Planetary Sciences (EAPS). "We think we have witnessed the asteroid losing its reddish dust to space, and we are seeing the asteroid's underlying, fresh blue layers."

Marsset and his colleagues have also confirmed that the asteroid is rocky — proof that the asteroid's tail, though seemingly comet-like, is caused by an entirely different mechanism, as comets are not rocky but more like loose snowballs of ice and dust.

"It's the first time to my knowledge that we see a rocky body emitting dust, a little bit like a comet," Marsset says. "It means that probably some mechanism responsible for dust emission is different from comets, and different from most other active main-belt asteroids."

Marsset and his colleagues, including EAPS Research Scientist Francesca DeMeo and Professor Richard Binzel, have published their results today in the journal Astrophysical Journal Letters.