Archive for May, 2011

Is there “life” beyond the orbit of Neptune?

Gy. M. Szabo, K. Sarneczky, L. L. Kiss / ESO

Without a doubt, one of the brightest comets of the past century is the well-known comet Hale-Bopp. This gigantic comet, possibly the biggest known, decorated the northern sky for many months! Many of today’s amateur astronomers came into astronomy specifically because of this heavenly guest.

Comet C/1995 O1 (Hale-Bopp) passed perihelion April 1, 1997, but observations still continue! Of course, it is no longer within reach of amateur telescopes, but it remains an attainable goal for the large observatories of the world. The latest observation of the comet was Deceber 4, 2010 with the 2.2 meter telescope of the Southern European Observatory (ESO, LaSilla, Chile). Notable is the fact that for the most “distant” observations of the comet, at the moment of imaging of C/1995 O1 it lay 30.7 a.u. from the Sun. That is, farther than the orbit of Neptune! Of course, we should take into account the practically perpendicular inclination of the comet’s orbit to the plane of the ecliptic.

In the images the comet was found not far from the calculated position, and appeared starlike with a brightness of mag. 23.3. In comparison with images from three years ago, the external appearance of the comet has greatly changed. The reflective surface area has decreased by a factor of nine, to 485 km?. From these and earlier estimates, the diameter of the comet’s nucleus is 60-70 km. One can conclude that the comet nucleus is surrounded by a very diffuse small coma, i.e. Comet Hale-Bopp remains active even at a distance of more than 30 a.u. (4.488 billion km) from the Sun!

Astronomers have also estimated the temperature of its surface – 53.1K. In their opinion, the comet’s activity may stop at a temperature of 50-53K, but that means it is possible that we are seeing signs of “life” in the comet for the last time. Very soon the nucleus of the comet will completely freeze for thousands of years. The Sun will once again melt the comet’s ice in another 2500 years.

From material in arXiv:1104.4351v1 [astro-ph.EP]

Debunking rumors of comet Elenin on one of the main Russian TV channels

Comet Elenin spawned mass hysteria on the Internet

A misreported April Fool’s joke sparked panic on the internet over a comet discovered by a Russian astronomer. Conspiracy theorists believe that the Elenin comet is an alien spaceship and demand that the scientist discloses data hushed up by NASA.

The web uproar focuses on the comet C/2010 X1, which was first discovered on December 10, 2010. Alien enthusiasts believe that it has a cluster of alien-made objects, most likely spacecraft, hiding in its tail. They fear that when the comet gets closer to Earth, the aliens will show themselves, and the first contact is likely to be a disaster. They expect doomsday on September 10.

The panic-sparking claims originate from Argentinean astronomer Sergio Toscano, whose report on the alien theory was cited by a number of Latin American media outlets. The scientist said the data came from the Chinese national space agency.

But the true origin of the story comes from a British newspaper, which published it as an April Fool’s joke. The astronomer may have been misguided by the fact that the Latin American counterpart for April Fool’s Day, Feast of the Holy Innocents, is celebrated on December 28.

Nevertheless, the internet rumor mill was quick to spread the story, which mutated into an alien invasion scare. Some even matched the comet with the infamous Nibiru planet.

“Non-existent” scientist’s misadventure

And the person arguably affected most by the scare is the Russian scientist who discovered the comet in the first place. Leonid Elenin from the Keldysh Institute of Applied Mathematics in Moscow became the first target for the enquiries, demands and threats of all the worried souls.

“It was somewhat funny at first, and I even surfed the internet to see what they say, but now I’m scared to do it. I’m really irritated. I’m really disappointed that this nonsense appeared in the Russian segment of the web,” the astronomer told RIA Novosti news agency.

According to Elenin, conspiracy theorists go as far as claiming that he is a front firm for NASA or other government agencies, who try to put a lid on the information about the alleged upcoming disaster.

“I’ve seen discussions about what Leonid Elenin actually means. ‘Ele’ is ‘extinction level event’ and ‘nin’ is Nibiru in November,” the scientist said.

The astronomer did his best to explain that there is nothing special about the comet he detected, apart from the fact that it was the first comet discovered by a Russian astronomer in two decades.

He believes the hysteria has been fueled by the photo of the comet made by a tracking camera, which resulted in two nearby stars leaving stretched markings.

“There’s the comet flying and there are tracks from the two stars. I read an article claiming those two ‘cylinders’ are the spacecraft,” Elenin explained.

The Elenin comet is to flyby Earth at an estimated distance of 35,000,000 kilometers in mid-October. You would need good binoculars or a telescope to see it harmlessly pass and go away.

Comet Elenin may be brighter than expected

A. Novichonok

Comet C/2010 X1 (Elenin) is becoming one of the most observed long-period comets. At the moment, the overall number of CCD camera observations is approaching 1300, while the number of CCD observations of comet C/1996 B2 (Hyakutake) never exceeded 1000. Of course, for the most part that reflects the growth and accessibility of modern CCD cameras. I have underscored this fact for the conspiracy theorists who are saying that Comet Elenin is impossible to see in the sky and all its observations are being kept secret. Of course that is not the case, but let’s return to news about the comet.

On the basis of quality estimates of the comet’s brightness, the photometric model of comet C/2010 X1 (Elenin) has been revised by Artem Novichonok. According to the new prediction, the comet may reach a brightness of mag. 4 near perihelion, and that is without accounting for the effect of forward scattering, when the comet is directly between the Earth and the Sun. Tiny icy dust particles will scatter light passing through them, and the comet’s brightness, which we can observe on images taken by SOHO’s space coronagraph, will increase. The comet could reach mag. 0 or even brighter! True, such a sharp increase in brightness will be very brief, and when the comet comes out of conjunction with the Sun and we can see it in the morning sky, its brightness will have already returned to mag. 4-4.5. The comet will remain visible to the unaided eye until the beginning of November.

May 2011
« Apr   Jun »