Volcanoes on venus

Venus has more volcanoes than any other planet in the solar system. Over 1600 major volcanoes or volcanic features are known, and there are many, many more smaller volcanoes.

Venus is like Earth in many ways. It is nearly the same size and it has a similar bulk composition. Of all the planets, its orbit around the sun is the closest to Earth's orbit. It has both clouds and a thick atmosphere. Like the Earth, it even has a fairly young surface age (~500 million years). Despite these basic similarities, however, Venus differs greatly from the Earth in detail.
First, since the atmosphere is mostly CO2, Venus has an extreme Greenhouse Effect. In fact, the surface temperature on Venus is about 470!C (about 880!F). Further, the surface air pressure on Venus is about 90 times greater than that at sealevel on Earth. This is roughly equivalent to the WATER pressure on Earth one kilometer beneath the oceanUs surface. These surface conditions have two effects. (1) There is no water on the surface of Venus. Indeed, there is almost no water in the air, either. The clouds are mostly made of sulfuric acid and they are much, much higher than most clouds on the Earth. (2) Due to the high atmospheric pressure, the winds on Venus are also relatively slow. Thus, neither wind nor rain can really affect the surface on Venus. As a result, volcanic features will look freshly formed for a long time.

Second, Venus shows no evidence for plate tectonics. There are no long, linear volcano chains. There are no clear subduction zones. Although rifts are common, none look like the mid-ocean ridges on Earth. Also, continent-like regions are rare, and show none of the jigsaw fits seen on Earth. Thus, where volcanism on Earth mostly marks plate boundaries and plate movements, volcanism on Venus is much more regional and much less organized.

Third, volcanism on Venus shows fewer eruptive styles than on the Earth. Almost all volcanism on Venus seems to involve fluid lava flows. There is no sign of explosive, ash-forming eruptions on Venus, and little evidence for the eruption of sludgy, viscous lavas. This may reflect a combination of several effects. First, due to the high air pressure, venusian lavas need much higher gas contents than Earth lavas to erupt explosively. Second, the main gas driving lava explosions on Earth is water, which is in very short supply on Venus. Lastly, many viscous lavas and explosive eruptions on Earth occur near plate subduction zones. Thus, the lack of subduction zones should also reduce the likelihood of such eruptions on Venus.

A mysterious light spotted in the newly discovered Gliese 581 Star System

A mysterious pulse of light was picked up from the direction of newly discovered earth like planet almost two years ago.
A scientist, Dr. Ragbir Bhathal at the University of Western Sydney, picked up the odd signal in December 2008, long before it was announced that the Gliese 581 star system has habitable planets in orbits arount it.
Dr. Bhathal had been sweeping the skies when he discovered a 'suspicious' signal from the direction of the galaxy that holds the newly discovered Gliese 581g.

The remarkable coincidence adds another layer of mystery to the announcement that scientists had discovered another planet in the system: Gliese 581g - the most earth like planet ever found.
This dicovery had come just months before astronomers announced that they had found a similiar, alightly less habitable planet around the same star which is 20 light years away. This planet was called Gliese 581e.

When asked about this discovery Dr Ragbir said that:
'Whenever there’s a clear night, I go up to the observatory and do a run on some of the celestial objects. Looking at one of these objects, we found this signal.
'And you know, I got really excited with it. So next I had to analyse it. We have special software to analyse these signals, because when you look at celestial objects through the equipment we have, you also pick up a lot of noise.'
He went on: 'We found this very sharp signal, sort of a laser lookalike thing which is the sort of thing we’re looking for - a very sharp spike. And that is what we found. So that was the excitement about the whole thing.'

For months the astronomers have been scanning the skies for a second signal to see whether there is a chance for the extra terrestrials to exist.

Mankind has always hoped that they were not the only ones in this entire universe, if this is the case there can really be a possibility that in a distant earth like planet the extra terrestrials might actually exist.
Still the search for aliens in going on and we hope to find their existence in the near future.

Gliese 581g - a new planet like Earth

Astronomers have found a planet that is in the Goldilocks zone- just right for life. It is in the same Gliese star system like the other planets such as 581c, 581d, 581e.

But unlike others this Earth-size planet has been spotted orbting its nearby star at a distance that would make it not too hot and not too cold - comfortable enough for life to exist. If confirmed, this planet, Gliese 581g, would be the first Earth-like planet found residing in the star's habitable zone where the planet's temperature could sustain liquid water on its surface.

The astronomers are optimistc about the prospects for finding life there.
"Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say, my own personal feeling is that the chances of life on this planet are 100 percent," said Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz, during a press briefing today. "I have almost no doubt about it."

This planet is found orbiting its red dwarf star Gliese 581, along with its other family of planets.
This star is located 20 light-years from earth in the constellation Libra. One light-year is about 6 trillion miles(10 trillion km).

Red dwarf stars are about 50 times dimmer than out sun. And hence these stars are so much cooler, their planets can orbit much closer to them and still remain in habitable zone.

Neptune - the ice giant

Neptune is the eighth and farthest planet from the Sun in the Solar System. Named for the Roman god of the sea, it is the fourth-largest planet by diameter and the third largest by mass. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times the mass of Earth but not as dense. On average, Neptune orbits the Sun at a distance of 30.1 AU, approximately 30 times the Earth–Sun distance. 


Neptune was the first planet to be identified by mathematical prediction rather than the empirical observation. The changes in the orbit of Uranus led to the deduction that there was a gravitational perturbation by an unknown planet. And hence neptune was found in 1846 through observation based on the mathematical prediction.


Triton,one of Neptune's moons. was discovered shortly thereafter, though none of the planet's remaining 12 moons were located telescopically until the 20th century.
The only spacecraft that has visited neptune was the voyager 2 which flew through that planet by the year of 1989.


Neptune is similar in composition to Uranus, and both have compositions which differ from those of the larger gas giants, Jupiter and Saturn. Neptune's atmosphere, while similar to Jupiter's and Saturn's in that it is composed primarily of hydrogen and helium, along with traces of hydrocarbons and possibly nitrogen, contains a higher proportion of "ices" such as water, ammonia and methane. Astronomers sometimes categorize Uranus and Neptune as "ice giants" in order to emphasize these distinctions. The interior of Neptune, like that of Uranus, is primarily composed of ices and rock. Traces of methane in the outermost regions in part account for the planet's blue appearance.


In contrast to the relatively featureless atmosphere of Uranus, Neptune's atmosphere is notable for its active and visible weather patterns. For example, at the time of the 1989 Voyager 2 flyby, the planet's southern hemisphere possessed a Great Dark Spot comparable to the Great Red Spot on Jupiter. These weather patterns are driven by the strongest sustained winds of any planet in the Solar System, with recorded wind speeds as high as 2,100 km/h. Because of its great distance from the Sun, Neptune's outer atmosphere is one of the coldest places in the Solar System, with temperatures at its cloud tops approaching −218 °C (55 K). Temperatures at the planet's centre are approximately 5,400 K (5,000 °C). Neptune has a faint and fragmented ring system, which may have been detected during the 1960s but was only indisputably confirmed in 1989 by Voyager 2.


Even though it is in the same solar system as earth and revolves around the same sun, our scientists know very little about this planet and are trying to study its nature.

'Hot Jupiter' planets might not have moons

Hundreds of large, hot, Jupiter-class planets have been discovered orbiting stars outside our solar system. They are called "hot Jupiter" planets because they are large and in close proximity of their stars. As yet no moons have been found circling these planets, but since large planets in our solar system have several moons they ought to exist.
The new research, led by french astronomers at the Observatoire de la Cote d'Azur in France, determined via computer simulations that moons orbiting or forming around hot Jupiter planets migrating close in to the star are unlikely to remain because of the large gravitational forces in play between the planet and star. The forces would destroy inner mooons as they smashed into the planet, while outlying moons would be catapulted out of the planet's orbit.
Hot Jupiter planets are believed to form in the outer regions of their solar systems and to migrate inwards towards their star over a period of around 100,000 years. They said that as the planet migrates its sphere of influence over any moons would shrink, making them unstable.
The computer simulation models a gas giant that migrates towards its star to become a hot Jupiter. At the beginning of the simulation the planet has four large moons, but all are lost during the migration. The three outermost moons are hurled out into elongated orbits around the star, while the innermost moon smashes into the planet and is destroyed.
They said that if any moons are found around a hot Jupiter they must have been captured later, rather like Neptune's Triton, which is the largest captured moon in the solar system. Triton is believed to have been captured because it orbits in the opposite direction to the other moons of Neptune.
The computer simulations did not take into account possible formation of moons from material orbiting the planet after a moon crashes into the surface.
Astronomers will continue to search for extrasolar moons around hot Jupiter planets because they are the vast majority of planets so far discovered. One way in which they plan to search for them is by observing hot Jupiters as they pass in front of their stars. Any large moons present would alter the timing of transits. Hot Jupiter be unable to support life, but this may not be true of any moons orbiting the planet.

Auroras occur on the icy planet of Uranus

The recent images taken by the Hubble space telescope has featured auroras on the icy planet of Uranus.

Uranus is the seventh planet revolving around the sun in our solar system. Named after the greek titan god of sky, this is the fourth largest planet in our solar system. 

The Hubble has spotted the appearance of auroras in the planet.  It is a rare phenomenon for a planet like Uranus to have auroras.

Even though those auroras are not similiar to those seen on the earth, they consist of faint glowing dots that lasts only for a minute and are fainter than those on earth.

Auroras are produced in the atmosphere as charged solar wind particles accelerate in the magnetosphere and are guided by the magnetic field close to the magnetic poles.

It also appears on the planets of Jupiter and Saturn like Earth, but since we know very less about the magnetosphere of the planet Uranus it is an unclear phenomenon.

A similiar one was detected 25 years ago by voyager 2 while flying by Uranus but the Hubble image looks different.

Uranus, unlike the other planets in that it it lies on its side, relative to the sun. Its magnetic axis is both offset from the center of the planet and tilts at an angle of 60 degrees from the rotational axis. Scientists theorize that the planet's magnetic field is generated by a salty ocean within the planet.

When Voyager 2 made its flyby, Uranus was near its solstice, with its rotational axis pointed toward the sun. That meant the magnetic axis was at a large angle from the solar wind flow, producing a magnetosphere similar to the Earth's.

Under those 1986 solstice conditions, the auroras lasted longer than the newly-seen ones and were mainly seen on the nightside of the planet.

The new set of observations, however, were made when the planet was near equinox, with the axis almost perpendicular to the solar wind flow. Because the planet's magnetic axis is tilted, the daily rotation of Uranus during the period around the equinox causes each of its magnetic poles to point once a day toward the sun.It is a unique configuration in the entire solar system.

Our scientists are in the process of studying the magnetosphere of Uranus inorder to get a better understanding of earth's magnetosphere.