Category: space

Why Is The Sky Dark At Night?

Why Is The Sky Dark At Night?

“The fact that saves us, which Olbers had no way of knowing back in his day, is not that the Universe isn’t infinite in extent (it still could be), but that it doesn’t go back, in its current form, for an infinite amount of time. The Universe we inhabit today had a beginning: a day without a yesterday. That beginning is known as the Big Bang, which puts a starting line for all the matter, radiation, energy, and light that possibly exists in the observable Universe.

The Universe hasn’t been around forever, and therefore we can only observe stars and galaxies that are a specific and finite distance away. Therefore, we can only receive a finite amount of light, heat, and energy from them, and there cannot be an arbitrarily large amount of light in our night sky.”

Ask a child what the color of the night sky is, and you’ll uniformly get the same answer: black. The night sky is one of the darkest things we have to look at in all of nature. And yet, the fact that the sky is completely dark at night is a bit of a paradox. If the Universe is full of light sources like stars and galaxies, and it’s truly infinite in extent, then no matter how far away you had to look to see it, eventually every line-of-sight you could imagine would end on a light source. Everywhere, in all directions, all you’d see was a bright light.

Yet, this clearly isn’t what happens in our Universe! This conundrum was known as Olbers’ Paradox, and was only solved in the 20th century. Here’s the ultimate answer!

The Perseid Meteor Shower Is Here, And Might F…

The Perseid Meteor Shower Is Here, And Might Foretell Humanity’s Extinction

“The Perseid meteor shower, even with a near-full Moon to contend with, should be one of the year’s most spectacular meteor showers. When you look up, scope out the northwest skies after sunset (from the northern hemisphere) and look for fast-moving streaks radiating away from near the “W” in Cassiopeia. A few dozen bright streaks per hour, even in the worst-case scenario, should still await you.

But as you watch the skies, keep in mind that there’s an enormous comet responsible for this light show, and it returns every 133 years. In just a handful of orbits, it will come closer to Earth than any reasonable person should be comfortable with. Even if it’s not Swift-Tuttle, it’s only a matter of time before an object just like it comes for us, threatening the extinction of humanity and much more. We have a choice: we can let it come, or we can be ready. Extinction by comet strike is, for the first time ever, no longer an inevitability. We just have to invest in our own cosmic safety to avoid this catastrophic fate.”

When a meteor shower comes our way, you likely look up at the sky and marvel. After all, why wouldn’t you? It’s one of the night sky’s most beautiful and natural sights. In the case of the Perseids, whose peak is just around the corner, it’s the most spectacular show of the year. Even when there’s a near-full Moon to contend with, like this year, it’s still worth taking a look at one of nature’s most wondrous occurrences.

Too bad that this one, in particular, may foretell the demise of not only humanity, but the overwhelming majority of species on Earth. The comet that created the Perseids is still coming, and it’s more dangerous than ever. Find out why.

Starts With A Bang Podcast #47 – Ice Giants …

Starts With A Bang Podcast #47 – Ice Giants At The Solar System’s Edge

What do we really know, and what mysteries are left to solve, about the outer worlds of our Solar System, and about the gas giant and ice giant worlds found throughout the Universe? Remarkably, if you had asked this same question 30 years ago, we would have had a quaint story about how planets form and why our Solar System has the planets it does, and we assumed that these rules would be extended to all solar systems in the galaxy and Universe. But with the deluge of exoplanet data, accompanied by better observations and simulations of our Solar System, that old story isn’t even the half of it.

I’m so lucky to get to interview Heidi Hammel for this edition of the podcast, who, as a bonus, was the lead investigator on the Hubble Space telescope when Comet Shoemaker-Levy 9 impacted Jupiter back in 1994! Come listen to one of my favorite interviews ever today!

(Image credit: NASA/Voyager 2)

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Double joke

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Wow 😂 (by @perryfellow on instagram)

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Fun-o-fact #1

If two pieces of the same type of metal touch in space, they will bond and be permanently stuck together.

Celebrate Earth Day With The Greatest Images O…

Celebrate Earth Day With The Greatest Images Of Our Planet From Space

“Our constant monitoring irrefutably demonstrates human-caused terrestrial changes. And an unambiguously rotating, revolving planet. Still, venturing farther away reveals Earth’s cosmic insignificance. From interplanetary space, our details become blurred and fuzzy. […] But as we venture to the outer planets, we’re barely a speck. From the edge of the Solar System, we’re hardly visible at all. In all the Universe, only Earth is home to humanity.”

Today is April 22nd: Earth Day. This is the one day where we’re supposed to take the time to value and appreciate the only home we’ve ever known, and the only planet that we’re aware of capable of supporting life on it. It is small; it is fragile; it is precious. But it’s also beautiful beyond comparison, and perhaps the best way to appreciate it all is to view it from a perspective that most of us will never have for ourselves: from space.

Celebrate Earth Day in unique fashion by viewing some of the greatest images ever taken of our world from beyond it. And happy Earth Day to every one of you.

Celebrate Earth Day With The Greatest Images O…

Celebrate Earth Day With The Greatest Images Of Our Planet From Space

“Our constant monitoring irrefutably demonstrates human-caused terrestrial changes. And an unambiguously rotating, revolving planet. Still, venturing farther away reveals Earth’s cosmic insignificance. From interplanetary space, our details become blurred and fuzzy. […] But as we venture to the outer planets, we’re barely a speck. From the edge of the Solar System, we’re hardly visible at all. In all the Universe, only Earth is home to humanity.”

Today is April 22nd: Earth Day. This is the one day where we’re supposed to take the time to value and appreciate the only home we’ve ever known, and the only planet that we’re aware of capable of supporting life on it. It is small; it is fragile; it is precious. But it’s also beautiful beyond comparison, and perhaps the best way to appreciate it all is to view it from a perspective that most of us will never have for ourselves: from space.

Celebrate Earth Day in unique fashion by viewing some of the greatest images ever taken of our world from beyond it. And happy Earth Day to every one of you.

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