For centuries, human beings have wondered about the possibility of other Earths orbiting distant stars. Perhaps some of these alien worlds would harbor strange forms of life or have unique and telling histories or futures. But it was only in 1995 that astronomers spotted the first planets orbiting sunlike stars outside of our solar system.
In the search for life beyond Earth, scientists have turned up some very interesting possibilities and clues. On Mars, there are currently eight functioning robotic missions on the surface of or in orbit investigating the possibility of past (and possibly present) microbial life. Multiple missions are also being planned to explore moons like Titan, Europa, and Enceladus for signs of methanogenic or extreme life.
Astronomers first noticed an enigmatic object, dubbed “Sagittarius A*”, at the very heart of our Milky Way galaxy in the 1960s – the earliest days of radio and infrared astronomy. But just how extraordinary this source was only became clear three decades later, when it was identified as a supermassive black hole with the mass of whopping four million suns.
This past weekend, a lot of attention was focused on the Tiangong-1 space station. For some time, space agencies and satellite trackers from around the world had been predicting when this station would fall to Earth. And now that it has safely landed in the Pacific Ocean, many people are breathing a sigh of relief. While there was very little chance that any debris would fall to Earth, the mere possibility that some might caused its share of anxiety.
Although radically different in terms of their content and feel, the range of dream states are just as complex as waking states. If we look across an individual’s lifetime, we find that children’s dreams are very different from adults’ dreams. Children tend to dream of emotional interactions with family members, friends and scary animals, while adults dream of other adults. Dreams of young adults are filled with social interactions between the dreamer and current friends and significant others. Men’s dreams differ substantially from women’s dreams, with women dreaming equally often of men and women, and men dreaming more often about other men. Older adults tend to dream more about creative works, legacies and enduring concerns, while the dreams of dying people are filled with numbers of supernatural agents, other-worldly settings and images of reunions with a loved one who has died. Dreams that transport the child into the social world of his caretakers during early life gently escort the dreamer into the arms of his loved ones when life is nearing an end. Dreams accompany us literally from the cradle to the grave.
Mercury is the closest planet to the sun, but far from being a dull cinder of a world, it has instead turned out to be a real eye opener for geologists. Among the revelations by NASA’s MESSENGER probe, which first flew past Mercury in 2008 and orbited it between 2011 and 2015, is the discovery of a hundred or so bright red spots scattered across the globe. Now they are at last being named.
Earth’s magnetic field is one of the most mysterious features of our planet. It is also essential to life as we know it, ensuring that our atmosphere is not stripped away by solar wind and shielding life on Earth from harmful radiation. For some time, scientists have theorized that it is the result of a dynamo action in our core, where the liquid outer core revolves around the solid inner core and in the opposite direction of the Earth’s rotation.
One of the defining characteristics of the modern era of space exploration is the way the public and private aerospace companies (colloquially referred to as the NewSpace industry) and are taking part like never before. Thanks to cheaper launch services and the development of small satellites that can be built using off-the-shelf electronics (aka. CubeSats and microsats), universities and research institutions are also able to conduct research in space.
When fossil collector Paul De la Salle discovered pieces of a giant bone on Lilstock beach in Somerset in May 2016, he didn’t realise he had stumbled on a clue to a near 170-year-old mystery. Returning to the beach the following month, he found more pieces that together measured about a metre in length. De la Salle realised he was looking at the lower jaw of a huge ichthyosaur, an ancient type of marine reptile that lived at the same time as the dinosaurs.
In February of 2016, scientists working for the Laser Interferometer Gravitational-Wave Observatory (LIGO) made history when they announced the first-ever detection of gravitational waves. Not only did this discovery confirm a century-old prediction made by Einstein’s Theory of General Relativity, it also confirmed the existence of stellar binary black holes – which merged to produce the signal in the first place.
Earth’s crust is made up of fractured slabs of rock, like a broken shell on an egg. These plates move around at speeds of about 5cm per year – and eventually this movement brings all the continents together and form what is known as a supercontinent. The last supercontinent on Earth was Pangaea, which existed between 300-180m years ago.
Volcanic activity on Io was discovered by Voyager 1 imaging scientist Linda Morabito. She spotted a little bump on Io’s limb while analyzing a Voyager image and thought at first it was an undiscovered moon. Moments later she realized that wasn’t possible — it would have been seen by earthbound telescopes long ago. Morabito and the Voyager team soon came to realize they were seeing a volcanic plume rising 190 miles (300 km) off the surface of Io. It was the first time in history that an active volcano had been detected beyond the Earth.
When stars reach the end of their main sequence, they undergo a gravitational collapse, ejecting their outermost layers in a supernova explosion. What remains afterward is a dense, spinning core primarily made up of neutrons (aka. a neutron star), of which only 3000 are known to exist in the Milky Way Galaxy. An even rarer subset of neutron stars are magnetars, only two dozen of which are known in our galaxy.
