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This is an “extremely close,” albeit safe, approach, with the object passing at a distance equivalent to around 13 percent of the average distance between our planet and the moon, astronomer Gianluca Masi from the Virtual Telescope Project told Newsweek.

The object, which is estimated to measure between 15–33 feet across, was discovered by the Pan-STARRS survey based in Maui, Hawaii, on September 17, 2020. This find was confirmed two days later by the Minor Planet Center, which is responsible for the designation of minor bodies in the solar system.

Initial observations suggested that the object was an asteroid. But scientists at CNEOS soon began to suspect that 2020 SO was not a normal asteroid.

Shockingly, Carroll notes that if our own Earth had formed just one percent farther away from the Sun, it would have suffered a runaway glaciation. By contrast, one percent further in and Earth would have suffered a runaway greenhouse and the fate that befell present-day Venus. “The habitable zone is a planetary tightrope,” writes Carroll.

However, the book does cover the possibility that super-earths and/or gas giant planets that lie in their parent stars’ habitable zones might also harbor planet-sized moons. As the book notes, it’s an idea that Hollywood director James Cameron’s embraced in his ground-breaking movie “Avatar.”

“Envisioning Exoplanets” also offers the reader capsule summaries of the various detection techniques that astronomers have used through the years to remotely explore and characterize these far-flung worlds.

Welcome back to our series on Martian colonization! In Part I, we looked at the challenges and benefits of colonization. In Part II, we looked at what it would take to transport people to and from Mars. In Part III, we looked at how people could live there. Today, we will address the question of how people could establish an industrial base there.

If we intend to “go interplanetary” and establish a colony on Mars, we need to know how to address the long-term needs of the colonists. In addition to shelter, air, water, food security, and radiation shielding, the people will need to create an economy of sorts. The question is, what kind of industry would Mars support?

There’s Gold in Them Thar’ Hills!

One of the main reasons why Mars is considered an attractive location for a colony is the similarities it has to Earth. Like Earth, it’s a terrestrial (aka. rocky) planet that’s composed primarily of metals and silicate minerals, which are differentiated between a metallic core and a silicate mantle and crust.

Distant light from the big bang is twisted as it travels to us. This could mean dark matter is more exotic than we thought.


The oldest light in the universe is that of the cosmic microwave background (CMB). This remnant glow from the big bang has traveled for more than 13 billion years. Along the way, it has picked up a few tales about the history and evolution of the cosmos. We just need to listen to what it has to say.

One of the ways the CMB tells a story is through its polarization. If you think of light as an oscillating wave, then this wave motion can have different orientations, the orientation of a light wave’s oscillation is known as its polarization. Often, light is a random jumble of orientations, making it unpolarized, but the light from the CMB is light that has scattered off the hot gas of the early universe and has an orientation known as E-mode polarization.

If there were nothing but empty, flat space between us and the cosmic microwave background, then all the light from the CMB would be E-mode polarized. But deep space isn’t empty. It’s filled not only with diffuse gas and dust, but also dark matter and dark energy. As the light from the big bang travels through this, its polarization changes slightly, twisting through an angle,? This shifts the orientation of CMB light toward B-mode polarization.