If the power goes out in your home, you can usually settle in with some candles, a flashlight, and a good book. You wait it out, because the lights will probably be back on soon.

Nearly 70 years ago, astronomer Paul Merrill was watching the sky through a telescope at Mount Wilson Observatory in Pasadena, California. As he observed the light coming from a distant star, he saw signatures of the element technetium.

The ALMA and APEX telescopes have peered deep into space — back to the time when the Universe was one tenth of its current age — and witnessed the beginnings of gargantuan cosmic pileups: the impending collisions of young, starburst galaxies.

Most of us have looked up at the night sky and wondered how far away the stars are or in what direction they are moving. The truth is, scientists don’t know the exact positions or velocities of the vast majority of the stars in the Milky Way. But now a new tranche of data from the European Space Agency’s Gaia satellite, aiming to map stars in our galaxy in unprecedented detail, has come in to shed light on the issue.

The Transiting Exoplanet Survey Satellite (TESS), NASA’s latest exoplanet-hunting space telescope, was launched into space on Wednesday, April 18th, 2018. As the name suggests, this telescope will use the Transit Method to detect terrestrial-mass planets (i.e. rocky) orbiting distant stars. Alongside other next-generation telescopes like the James Webb Space Telescope (JWST), TESS will effectively pick up where telescopes like Hubble and Kepler left off.

Veils of dust wrapped around distant stars could make it difficult for scientists to find potentially habitable planets in those star systems. The Hunt for Observable Signatures of Terrestrial Systems, or HOSTS, survey was tasked with learning more about the effect of dust on the search for new worlds. The goal is to help guide the design of future planet-hunting missions. In a new paper published in the Astrophysical Journal, HOSTS scientists report on the survey’s initial findings.

These NASA Hubble Space Telescope images compare two diverse views of the roiling heart of a vast stellar nursery, known as the Lagoon Nebula. The images, one taken in visible and the other in infrared light, celebrate Hubble’s 28th anniversary in space.

NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission has released its fourth year of survey data. Since the mission was restarted in December 2013, after a period of hibernation, the asteroid- and comet-hunter has completely scanned the skies nearly eight times and has observed and characterized 29,375 objects in four years of operations. This total includes 788 near-Earth objects and 136 comets since the mission restart.

Since the beginning of the Space Age, humans have relied on chemical rockets to get into space. While this method is certainly effective, it is also very expensive and requires a considerable amount of resources. As we look to more efficient means of getting out into space, one has to wonder if similarly-advanced species on other planets (where conditions would be different) would rely on similar methods.

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.

Step outside on a clear night, and you can be sure of something our ancestors could only imagine: Every star you see likely plays host to at least one planet.

The Moon and Mars will probably be the first places in the Solar System that humanity will try to live after leaving the safety and security of Earth. But those worlds are still incredibly harsh environments, with no protection from radiation, little to no atmosphere, and extreme temperatures.

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.

Forty-five years have passed since humans last set foot on an extraterrestrial body. Now, the moon is back at the center of efforts not only to explore space, but to create a permanent, independent space-faring society.

When searching for extra-solar planets, astronomers most often rely on a number of indirect techniques. Of these, the Transit Method (aka. Transit Photometry) and the Radial Velocity Method(aka. Doppler Spectroscopy) are the two most effective and reliable (especially when used in combination). Unfortunately, direct imaging is rare since it is very difficult to spot a faint exoplanet amidst the glare of its host star.

I saw my first artificial satellite with my naked eyes during the summer of 1994. I was watching pieces of comet Shoemaker-Levy 9 impact Jupiter from a small observatory with a college astronomy club when someone pointed up – away from the telescope – and said, “Look, it’s a satellite!”