“A brief and unusual flash spotted in the night sky on June 16, 2018, puzzled astronomers and astrophysicists across the globe. The event - called AT2018cow and nicknamed “the Cow” after the coincidental final letters in its official name - is unlike …

“Using data from NASA’s Kepler space telescope, citizen scientists have discovered a planet roughly twice the size of Earth located within its star’s habitable zone, the range of orbital distances where liquid water may exist on the planet …

“NASA’s Transiting Exoplanet Survey Satellite (TESS) has found three confirmed exoplanets, or worlds beyond our solar system, in its first three months of observations. The mission’s sensitive cameras also captured 100 short-lived changes — most of them likely stellar …

“Scientists at last have their first good look at a primordial piece of the solar system orbiting more than four billion miles away. On the final evening of 2018, the biggest New Year’s Eve party in the solar system …

“At 2:43 p.m. EST on December 31, while many on Earth prepared to welcome the New Year, NASA’s OSIRIS-REx spacecraft, 70 million miles (110 million kilometers) away, carried out a single, eight-second burn of its thrusters …

“An adolescent star in the midst of a dramatic growth phase has been observed with the help of two NASA space telescopes. The youngster belongs to a class of stars that gain mass when matter swirling around the star falls …

“NASA’s InSight lander has deployed its first instrument onto the surface of Mars, completing a major mission milestone. New images from the lander show the seismometer on the ground, its copper-colored covering faintly illuminated in the Martian dusk. It …

“It looks like NASA chose the right space rock for its asteroid-sampling mission. The agency’s OSIRIS-REx probe, which just arrived at Bennu last week, has already found hydrated minerals on the 1,640-foot-wide (500 meters) near-Earth asteroid, mission …

“For the second time in history, a human-made object has reached the space between the stars. NASA’s Voyager 2 probe now has exited the heliosphere - the protective bubble of particles and magnetic fields created by the Sun. Members of …

“Nine U.S. companies now are eligible to bid on NASA delivery services to the lunar surface through Commercial Lunar Payload Services (CLPS) contracts, as one of the first steps toward long-term scientific study and human exploration of the Moon …