Tuesday, June 19, 2018
3 from Nasa Apod
from: NASA APOD
Ancients of Sea and Sky
Image Credit & Copyright:
They may look like round rocks, but they're alive.
Moreover, they are modern versions of one of the oldest known forms of life:
Fossils indicate that
stromatolites appeared on Earth about 3.7 billion years ago -- even before many of the
familiar stars in the modern night sky were formed.
In the featured
image taken in
Western Australia, only the ancient central arch of our
Milky Way Galaxy formed earlier.
Magellanic Clouds, satellite galaxies of our Milky Way and visible in the featured image below the
Milky Way's arch, didn't exist in their current form when
stromatolites first grew on Earth.
Stromatolites are accreting biofilms of billions of
microorganisms that can slowly move toward light.
Using this light to
liberate oxygen into the air,
ancient stromatolites helped make
Earth hospitable to
other life forms including, eventually,
Red Cloudbow over Delaware
Image Credit & Copyright:
Michael C. Neff
What kind of rainbow is this?
In this case, no rain was involved -- what is pictured is actually a red
The unusual sky arc was spotted last month during sunset in
When the photographer realized that what he was seeing was
extraordinary, he captured it with the only camera available -- a cell
Clouds are made of water droplets, and in a cloudbow a
cloud-droplet group reflects back light from the bright Sun (or Moon) on the opposite side of the sky.
Similar phenomena include
Here, the red color was caused by atmospheric air preferentially scattering away blue light -- which simultaneously makes most of the
sky appear blue.
A careful inspection reveals a
supernumery bow just inside the outermost arc, a bow caused by
Jupiter Season, Hawaiian Sky
Image Credit &
activity on the Big Island of Hawaii has increased
since this Hawaiian night skyscape was recorded earlier this year.
Recent vents and lava flows
are about 30 kilometers to
the east, the direction of the blowing smoke and steam in the
panoramic view of the Kilauea caldera with Halemaumau crater taken from
Volcanoes National Park.
Still, this year Jupiter is
bright in late spring to early summer skies.
High in the south it is easily the brightest celestial beacon
in the scene where the central bulge of the Milky Way seems to rise
above vapors and clouds.
Yellowish Antares is the bright star near the end of the
of dust seen toward the center of our galaxy.
Near the horizon, stars Alpha and Beta Centauri
and the compact
Southern Cross shine through the almost
too bright volcanic smoke.