Last week, scientists announced the 1st known source for ghostly, high-energy neutrinos. The source is a blazar, a billion-solar-mass black hole 3.7 billion light-years away. The discovery establishes a new way to study the universe.
Mysterious ‘Oumuamua is the 1st confirmed interstellar object to pass through our solar system.
Artist impression of the interstellar object ‘Oumuamua. Image via ESA/Hubble, NASA, ESO, M. Kornmesser.
The best time to see Mars since 2003 is now! Watch for Mars as the extremely bright red “star,” ascending in the east by mid-evening, crossing the sky for the rest of the night. Photos from the EarthSky community here.
Mars on July 14, from Johnnyxbox Childers, who wrote: "Bright Mars captured in the wee minutes of Saturday, while practicing new photographic techniques."
Asteroid 2017 YE5 swept by Earth in late June. Turns out, it’s a double asteroid, with both bodies almost identical in size and not touching – only the 4th such object ever detected.
Bi-static radar images of the binary asteroid 2017 YE5 from the Arecibo Observatory and the Green Bank Observatory on June 25. The observations show that the asteroid consists of two separate objects in orbit around each other. Image via Arecibo/GBO/NSF/NASA/JPL-Caltech.
An explanation of why extra-close perigees and extra-far apogees happen at new and full moons.
Diagram via Bedford Astronomy Club
. The line connecting lunar perigee with lunar apogee defines the moon's major axis. At (A) the major axis is pointing directly at the sun, maximizing the eccentricity of the moon's orbit. At this juncture, perigee is less distant and apogee more distant, giving rise to a perigee new moon (supermoon) and an apogee full moon (micro-moon). Then, 3.5 lunar months (103 days) later, at (B), the moon's major axis makes a right angle to the sun-Earth line. This minimizes the eccentricity, lessening the apogee distance yet increasing the perigee distance. Then 7 lunar months (206 days) after the major axis points directly at the sun at (A), it points toward the sun at (C) - except that it's an apogee new moon (micro-moon) and perigee full moon (supermoon). Generally, the closest perigee comes at full moon and the farthest apogee at new moon.
This Friday the 13th comes exactly 13 weeks after 2018’s first Friday the 13th, in April. The whats, whens and whys of Friday the 13th.
Image via lesaffaires.
The closest new moon of 2018 – a supermoon – comes on July 13. You won’t see it, but Earth’s oceans will feel it. Then, 2 weeks later, we have the year’s farthest full moon.
A new moon is more or less between the Earth and sun. Its lighted half is turned entirely away from us. Image via memrise.com.
Those beams of light shooting out from the horizon or down from the clouds are called crepuscular rays, or sunrays. Beautiful, mysterious and very noticeable.
Image Nicholas Holshouser.
Earth transits seen from Pluto are rare. The last one happened in 1931, a year after Clyde Tombaugh discovered Pluto. It won’t happen again for 161 years.