1. The Aliens Are Silent Because They Are Extinct
Life on other planets would likely be brief and become extinct very quickly, said astrobiologists from the Australian National University (ANU).
Scientists realised most early planetary environments are unstable. To produce a habitable planet, life forms need to regulate greenhouse gases to keep surface temperatures stable. About 4 billion years ago, Earth, Venus, and Mars may have all been habitable. However, a billion years or so after formation, Venus turned into a hothouse and Mars froze into an icebox. Early microbial life on Venus and Mars, if there was any, failed to stabilize the rapidly changing environment, said Charley Lineweaver from ANU.
“Life on Earth probably played a leading role in stabilizing the planet’s climate,” he said.
“The mystery of why we haven’t yet found signs of aliens may have less to do with the likelihood of the origin of life or intelligence and have more to do with the rarity of the rapid emergence of biological regulation of feedback cycles on planetary surfaces,” he said. Wet, rocky planets with the ingredients and energy sources required for life seem to be ubiquitous. However, as Fermi pointed out in 1950, no signs of surviving extraterrestrial life have been found. A plausible solution to Fermi’s paradox, say the researchers, is near universal early extinction, which they have named the Gaian Bottleneck.
2. Voyager Mission Celebrates 30 Years Since Uranus
Humanity has visited Uranus only once, and that was 30 years ago. NASA’s Voyager 2 spacecraft got its closest look at the mysterious, distant, gaseous planet on Jan. 24, 1986.
Voyager 2 sent back stunning images of the planet and its moons during the flyby, which allowed for about 5.5 hours of close study. The spacecraft got within 50,600 miles (81,500 kilometers) of Uranus during that time.
3. Researchers see signs of a real Planet X
Caltech researchers have found evidence of a giant planet tracing a bizarre, highly elongated orbit in the distant solar system. The object, which the researchers have nicknamed Planet Nine, has a mass about 10 times that of Earth and orbits about 20 times farther from the Sun on average than does Neptune (which orbits the Sun at an average distance of 2.8 billion miles). In fact, it would take this new planet between 10,000 and 20,000 years to make just one full orbit around the Sun.
This artistic rendering shows the distant view from Planet Nine back towards the sun. The planet is thought to be gaseous, similar to Uranus and Neptune. Hypothetical lightning lights up the night side.
Fairly quickly Batygin and Brown realized that the six most distant objects from the 13 of most distant objects in the Kuiper Belt discovered by Chad Trujillo and Scott Shepherd all follow elliptical orbits that point in the same direction in physical space. That is particularly surprising because the outermost points of their orbits move around the solar system, and they travel at different rates.
“It’s almost like having six hands on a clock all moving at different rates, and when you happen to look up, they’re all in exactly the same place,” says Brown. The odds of having that happen are something like 1 in 100, he says. But on top of that, the orbits of the six objects are also all tilted in the same way — pointing about 30 degrees downward in the same direction relative to the plane of the eight known planets. The probability of that happening is about 0.007 percent. “Basically it shouldn’t happen randomly,” Brown says. “So we thought something else must be shaping these orbits.”
Where did Planet Nine come from and how did it end up in the outer solar system? Scientists have long believed that the early solar system began with four planetary cores that went on to grab all of the gas around them, forming the four gas planets — Jupiter, Saturn, Uranus, and Neptune. Over time, collisions and ejections shaped them and moved them out to their present locations. “But there is no reason that there could not have been five cores, rather than four,” says Brown. Planet Nine could represent that fifth core, and if it got too close to Jupiter or Saturn, it could have been ejected into its distant, eccentric orbit.
4. NASA Remembers Its Fallen Heroes, 30th Anniversary of Challenger AccidentNASA will pay will tribute to the crews of Apollo 1 and space shuttles Challenger and Columbia, as well as other NASA colleagues, during the agency’s Day of Remembrance on Thursday, Jan. 28, the 30th anniversary of the Challenger accident. NASA’s Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of space exploration. The Challenger Accident was a tragic day in spaceflight history when the Space Shuttle Challenger exploded on 28 January, 1986, killing 5 astronauts and 2 payload specialists 73 seconds into the flight.
5. See 5 planets aligned without a telescope!
For the first time in more than a decade, Mercury, Mars, Venus, Saturn, and Jupiter — the five planets bright enough to be seen with an unaided eye — will all be visible at once in the sky.
You’ll have to wake up early to catch it. Starting January 20, it will be possible to see all five planets in a row, about 45 minutes before sunrise, Sky and Telescope reports. The planets should be visible in this arrangement until February 20.
(Sky and Telescope notes it might get harder to see Mercury after the first week of February, because of its low position near the horizon).
This is the first time five planets have been aligned in a night sky since January 2005.
Mercury will appear lowest to the horizon, and its faint light will be hardest to spot in the southeastern sky (in the Northern Hemisphere). Then, from left to right (from southeast to southwest), you’ll be able to see Venus, Saturn, Mars, and Jupiter, in a line that roughly traces the path the sun will take through the day.
Because the planets orbit on a very similar plane as Earth does around the sun, they appear lined up in the sky.
You may be able to identify Venus first, as it will be the brightest object in the array (the only brighter objects in the sky overall are the sun and the moon). The five planets will cover a large swath of sky, so to view them all at once you’ll need to either be up high or have a view unobstructed by trees or buildings.
The alignment has no astronomical significance other than that it is rare — a coincidence that the five planets with their varying speeds and orbits appear in the same field of view. But it is cool nonetheless.