Sharpless 308: Star Bubble : Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 2-308 it lies some 5,200 light-years away toward the constellation of the Big Dog and covers slightly more of the sky than a Full Moon. That corresponds to a diameter of 60 light-years at its estimated distance. The massive star that created the bubble, a Wolf-Rayet star, is the bright one near the center of the nebula. Wolf-Rayet stars have over 20 times the mass of the Sun and are thought to be in a brief, pre-supernova phase of massive star evolution. Fast winds from this Wolf-Rayet star create the bubble-shaped nebula as they sweep up slower moving material from an earlier phase of evolution. The windblown nebula has an age of about 70,000 years. Relatively faint emission captured in the expansive image is dominated by the glow of ionized oxygen atoms mapped to a blue hue. via NASA
What color is Pluto? If you search for the dwarf planet on Google, images suggest that it’s a sort of steely blue or gray color. But now, NASA’s New Horizons spacecraft is closing in on it, and has learned Mars isn’t the only red planet in our solar system. But the reason it’s red couldn’t be more different from Mars.
To see more cosmically inspired photos and videos from Katrin, follow @k_koenning on Instagram.
If you were from space and landed on Earth for the first time, what would you photograph? Would airborne dust remind you of tiny galaxies? Could you capture planetary light in a portrait of a stranger? Welcome to the interstellar world of photographer Katrin Koenning (@k_koenning), a German-born photographer based in Melbourne, Australia. “I come from a story of movement, always on the periphery of multiple worlds,” says Katrin. “My thoughts are in the stars every day, and in a migrant existence, the idea of a shared sky is of great comfort. Physically I’ll never get to space, I know this. But I’ve come to understand that all it takes to travel to the stars is the mind. So I create my own universes, with whatever it is that’s around me.”
A few hundred million years following the Big Bang, the Universe was in darkness. This period marked the cosmic Dark Age in which no stars existed, and the initial flash of the Big Bang had gone out.
When the Universe first exploded into existence, the heat was so extreme that atoms were fully ionized by the sheer amount of energy. At this stage, the Universe was a churning mass of particles, free electrons, and gas. Light photons were unable to freely travel through this dense fog as they were constantly getting absorbed and re-emitted. This made the cosmos effectively opaque.
As the Universe began to cool, these components recombined, creating a gas of electrically neutral atoms. This allowed light particles to break free, and for the first time the cosmos became transparent. In the aftermath of these events, with no stars or galaxies in existence, the Universe plunged into the dark ages.
What happened during the cosmic Dark Age remains elusive, as the Earth will never receive visible light from this era. However, by analysing the cosmic microwave background radiation (CMBR), cosmologists are able to reconstruct the evolution of the early Universe and gain insight into this enigmatic era. The CMBR is a remnant of the oldest light in the cosmos, which shifted to a lower energy as the Universe expanded, and is now present as microwaves.
The Wilkinson Microwave Anisotropy Probe (WMAP) measured fluctuations in the CMBR across the entire sky. While the CMBR was fairly uniform in all directions, the satellite revealed tiny variations in temperature, which echo variations in the density of matter shortly after the Big Bang. By mapping the patterns in the CMBR, WMAP has provided accurate data on the effects of matter and energy on the infant Universe.
If the Universe had in fact burst forth in a colossal explosion, matter would not have been distributed evenly, but rather ejected in clumps. The denser regions of matter had a slightly stronger gravitational pull than their surrounding regions. Gradually, they accumulated matter, paving the way for large-scale structures, such as galaxies.
Throughout the cosmic Dark Age, matter continued to coalesce into the forms of the earliest stars and galaxies. As this progress was made in the “dark”, astronomers can’t view exactly what went on during this period. However, it is clear that later structures, such as stars, galaxies and galaxy clusters, were heavily influenced by these events.
By seeking to understand what went on during the cosmic Dark Age, we can move closer to understanding the Universe at large. Before the rise of the first stars there was darkness and this darkness marked a crucial stage in the evolution of our Universe.
IMAGE CREDIT SOURCES: 1, 2, 3, 4 Gilliland, Ben 2015, How to Build a Universe, Octopus Publishing Group, London.