Top 10 signs of alien life
10) Meteorites In 2011 a NASA scientist claimed to have found fossils of alien bugs inside meteorites that landed on Earth. The astro-biologist, Richard Hoover, said that laboratory tests on the meteorites contained no evidence to suggest that the fossils were of Earth-based organisms. The three meteorites are believed to be among the oldest in the solar system. Hoover claims that the lack of nitrogen in the samples, indicates that they are the remains of extraterrestrial life forms that grew on the parent bodies of the meteorites when liquid water was present. However, it has not been proven whether the meteorites contain fossils of extraterrestrial organisms. 9) Venus Clouds Astrobiologists have suggested that the acidic clouds of Venus could contain life. The atmosphere of Venus 30 miles (50 kilometres) above the planet’s surface has the most “Earth-like” conditions in our entire solar system, with a temperature and pressure similar to Earth. It also contains water vapour and small amounts of oxygen. Scientists have observed that Venus’s atmosphere contains the chemical carbonyl sulphide [car-bo-nil sul-fide], which on Earth is generally an indicator of biological activity. Even more convincing is the fact that bacteria shaped particles have been found in Venus’s clouds. 8) Viking Lander A re-interpretation of a NASA experiment has led some scientists to conclude that there is life on Mars. In 1976, NASA sent two Viking robots to Mars, in an attempt to detect life, but evidence for life, found in the results, was dismissed as Earth contaminants. However in 2008, when the robot Phoenix lander discovered powerful oxidising compounds in Martian soil, scientists at NASA were able to re-interpret the 1976 data and some scientists have suggested that Mars’s soil contains organic material. However, more tests are needed to prove conclusively that there is life on Mars. 7) Bacteria on Europa A NASA Astrogeophysicist has suggested that the red tinge of Jupiter’s moon Europa, could be evidence of frozen bacteria. Underneath its icy crust, Europa contains more liquid water than Earth, making it one of our Solar System’s most likely environments for hosting life, as it contains all of the key elements thought to be necessary for life. Infrared radiation on Europa is absorbed differently to normal ice and studies on Earth bacteria have led scientists to suggest that bacteria could live in Europa’s water. However, other scientists suggest that the colour of Europa and its mysterious absorption of infra-red signals is explained by the salts thought to be frozen in its ice surface. 6) Wow Signal In 1977 scientists at the Big Ear Radio Observatory, detected the now famous “Wow!” signal. The signal, possibly an alien pulse, was thirty times stronger than the background noise and observed on a frequency in which Earth transmitters are forbidden. The ‘Wow’ signal was focused and only heard on one of the observatory’s fifty channels, which supports the idea that it was an extraterrestrial transmission. Only lasting for 72 seconds, the signal rose and fell during that time, as would be expected from a signal originating deep in space. Despite repeated tests, the ‘Wow’ signal hasn’t been observed again and its origin remains a complete mystery. 5) Life on Titan Scientists at NASA suggest that methane-based life may exist on Saturn’s moon, Titan. Titan’s thick atmosphere is chemically active and rich in carbon compounds, the ingredients that many scientists believe contributed to the development of life on Earth. Meanwhile the surface of Titan is thought to be covered by seas of liquid methane. While all life on Earth uses water as a liquid solvent, some scientists suggest that methane could take the place of water in living cells different from those on Earth. Scientists analysing data from NASA’s Cassini probe that visited Titan’s atmosphere, reported that anomalies in the moon’s atmosphere, near the surface, would be consistent with life forms breathing in the planet’s atmosphere. However, NASA scientists admit that the anomalies may also be caused by meteorological processes. 4) Enceladus Scientists at NASA have suggested that Saturn’s moon Enceladus, may be the most habitable place in our Solar System beyond Earth. NASA’s probe has revealed that Enceladus has an internally heated saltwater ocean under its frozen south pole. It is the only place beyond Earth that is known to be hydrothermally active, with temperatures closest to the moon’s core reaching at least 194 fahrenheit, 90C . It is thought that similar hydrothermal vents on our ocean floors played a role in the emergence of life on Earth billions of years ago. 3) Alien Signal Since 2001, telescopes have been picking up fast radio bursts that seem to be following a mathematical pattern, suggesting they could be communication attempts from an extraterrestrial civilisation. Originating 5.5 billion light years away, the 10 recorded bursts have arrived at Earth in a pattern that doesn't match any known cosmic physics. Data analysts believe there is only a 5 in 10,000 chance that this pattern is a coincidence. Only lasting for a few milliseconds, their sources are thought to emit as much energy in that time as the Sun does in an entire day. However, scientists note that the pattern might disappear as more bursts are detected. Other theories suggest the bursts of energy could be from neutron stars or black holes. 2) Methane on Mars NASA's Curiosity rover on Mars has reported tentative signs of life on Mars of life, either in the past or present. Curiosity reported surprising spikes in methane gas, raising the possibility of microbial [my-crow-bee-al] alien life on the red planet. On Earth, most methane is released by microbes. The presence of Methane gas may also be geological, but methane delivered in this method should linger in the atmosphere for 300 years - Curiosity found that the gas had vanished within just a few weeks. 1) Goldilocks Planets Data from the Kepler space observatory has shown that Earth-like planets are a lot more common than previously thought. Astronomers have estimated that there could be as many as 11 billion habitable Earth-sized planets in our own galaxy that orbit the “Goldilocks” or “habitable zone”: a region where liquid water could exist on the planet’s surface and life could flourish. NASA’s Kepler space telescope has identified planet Kepler 438b as one of the most Earth-like planets outside of our solar system, in terms of size and temperature. Located 470 light years away, in the constellation of Lyra, Kepler 438b is slightly larger than our planet and receives 40% more heat than Earth receives from its sun. Kepler 438b is just one of eight Earth-sized planets recently found outside of our solar system that falls within the Goldilocks or habitable zone of their sun.
