lördag 18 juli 2026

Milky Way

Imagine being able to see our own galaxy, the Milky Way, with the naked eye. But you have to get away from all light pollution, away from cities and even local lights. The moon must not interfere either. Wait to get night vision (10-40 min), no lamp on or mobile phone on - then you will see the Milky Way as a band across the sky. These pictures were taken in Gekland and there you can also see the center of the Milky Way, which is seen as a large cloud in the night sky. This part of the Milky Way cannot be seen from Sweden.

The center of our galaxy is located 26,000 light-years away from Earth in the Sagittarius constellation. It features a supermassive black hole called Sagittarius A*, which is about 4 million times heavier than our Sun. Thick cosmic dust hides this busy, star-packed region from normal view.

Astronomers estimate that the Milky Way contains between 100 and 400 billion stars. Because we are inside the galaxy and obscured by thick clouds of gas and dust, we can only roughly calculate the total by measuring the galaxy's mass and observing the movement of its stars











fredag 17 juli 2026

Bright NLC´s

 

Noctilucent clouds are the highest clouds in Earth's atmosphere, forming in the mesosphere about 76 to 85 kilometers (50 miles) above the surface.

Meaning "night-shining" in Latin, they appear as electric-blue, silvery, or glowing wisps during summer deep twilight when they are illuminated by the sun from below the horizon.

Noctilucent clouds (NLCs), also called polar mesospheric clouds (PMCs) when viewed from space, are a tenuous atmospheric phenomenon. Unlike typical weather clouds that form less than 12 miles above Earth, NLCs occur at the very edge of space.How

For noctilucent clouds to form, three precise ingredients are required:

Extremely Low Temperatures: Temperatures in the mesosphere must drop below -120°C to -140°C.Water

Trace amounts of water vapor must be present.

Tiny dust particles are needed, primarily from micrometeors burning up in the atmosphere.

Water vapor freezes onto the meteoric dust to form microscopic ice crystals, which reflect sunlight. Their striking blue color is a result of the ice crystals scattering sunlight in the upper atmosphere.

Noctilucent clouds are a seasonal and latitudinal phenomenon. They occur only during the summer months when the upper atmosphere above the polar regions experiences its coldest temperatures.

Northern Hemisphere: Best viewed between mid-May and mid-August, primarily at mid-to-high latitudes (roughly 45° to 80° North, including northern Europe, Canada, and the northern United States).

Southern Hemisphere: Best viewed between mid-November and mid-February


Photos taken in Vallentuna Sweden 16-17/7 2026.










onsdag 15 juli 2026

Night sky disappearing?

Is this night sky soon gone forever?

We have light pollution, Starlink satellites, and soon maybe sun-reflecting satellites too?

 Light pollution is the overuse or misdirected use of human-made artificial lighting outdoors, altering natural light levels at night. This global environmental problem obscures the starry sky, wastes energy, and harms both human health and ecosystems.

 More than 10,000 Starlink satellites currently orbit the Earth. We see them crawling across dark skies, no matter how remote our location, and streaking through images from research telescopes.

SpaceX recently announced that it wants to launch one million more of these satellites as orbital data centres for AI computing power.

 Mirrors in Space? The FCC Just Approved a Sun-Reflecting Satellite, and Astronomers Are Worried

For now, a single satellite has been cleared for a test demonstration, but the company making it hopes to eventually launch 50,000 of them into orbit.

 This picture was taken on the southern part of the island of Zakynthos, Greece, during a family vacation. Most of the island has light pollution that ruins the night sky, so we took a drive to the southern part where there is no city. And the next mainland to the south is Libya, so the sky was amazingly dark and beautiful. The center of the Milky Way appeared as a cloud in the night sky.

 It would be devastating in many ways if the night sky disappeared more and more, even today not many people have seen a truly dark starry sky. The only way for us to realize our place in the universe, how small we are and that we have to take care of each other.