Like anything else, stars have life spans. They are born (from collapsing clouds of interstellar dust), they go through a long main phase where they fuse various elements in their cores, and eventually they die when they run out of fuel. The finer details of these steps are based on what the star is made of, how massive it is, and what sort of company it keeps. Stars like our Sun have lifespans in the 9-10 billion year range—of which ours is near the middle—but other stars can have much shorter or longer lifespans, and as astronomers look out into the galaxy they can find stars at all different phases of their lives…of course, the longer a phase lasts, the more likely it is to find stars existing within it. We’ve found stars that are only a few thousand years old and we know of regions where stars are, right now, in the process of being born, but what is the oldest star we know of?
Actually, it’s not all that far away, in cosmic terms. Just 190 light-years distant in our own galaxy, HD 140283 (aka the Methuselah star) is, as of 2013, the oldest star ever discovered. Based on its stage as a subgiant and its remarkably low amount of heavy elements, astronomers have estimated the age of this star as 14.3 billion years old. Now this number is actually more than the estimated age of the Universe itself, but don’t worry—there’s a reason for that.
Read the rest of this story by astronomer Phil Plait on Slate here: The Oldest Known Star in the Universe.
If you’re in love with space exploration then you’ll fall for this: a picture of Earth (and five other planets) taken from the Voyager 1 spacecraft after it passed the orbit of Pluto in 1990, 26 years ago today. That image of our planet from almost 4 billion miles away inspired Carl Sagan to write his famous “Pale Blue Dot” passage, and reminds us that we are all just floating on “a mote of dust suspended in a sunbeam.”
This is from a post I originally published in 2010. I’ll keep trotting it out until it’s not cool anymore. (Which
I don’t think will ever will NEVER happen.)
On February 14, 1990, after nearly 13 years of traveling the solar system, the Voyager 1 spacecraft passed the orbit of Pluto and turned its camera around to take a series of photos of the planets. The image above shows those photos, isolated from the original series and are left to right, top to bottom: Venus, Earth, Jupiter, Saturn, Uranus, and Neptune.
From that distance, over 4 billion miles from the Sun, the planets each appear as little more than a bright dot against the vastness of interplanetary space.
“That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. … There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world.”
– Carl Sagan
If you just looked at your calendar and realized you’re literally out of days (Happy New Year!) then it’s way past time to get yourself a new one. And if you love space, these are the ones you’ll want.
Produced by Starry Messenger Press in conjunction with The Planetary Society, the 2016 Year in Space calendar is (like its predecessors) a gorgeous 16″ x 22″ (40.5 cm x 56 cm) work of art filled with over 120 images of space exploration and hundreds upon hundreds of bits of information about everything space. Sure it tells you what date it is like any other calendar, but no other calendar I know gives you so much great information about cosmic objects, astronauts and scientists, worlds of our solar system, and daily space exploration history. If you love space then you owe it to yourself to get one of these on your wall NOW. (I just put mine up and instantly learned that Ceres was discovered on this day in 1801!)
And, because Lights in the Dark has your back (and its illustrious author is not only mentioned on the inside front cover but this year was also responsible for writing all of the 53 photo descriptions on the desk version) you can get a discount by mentioning that you saw it on the internet. Order details are below:
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It’s coming — on September 27 there will be a total lunar eclipse, the entirety of which will be visible across much of the western hemisphere! During total lunar eclipses the Moon passes through the shadow of Earth cast by the Sun, and is colored by dusky blue, purple, and crimson light as its normally harsh glare is briefly reduced to nearly nothing before the process reverses. It’s a beautiful cosmic event to behold and this year it’s an extra special treat — not only will the Moon be totally eclipsed but it will also be at perigee, the closest point to Earth along its 27.3-day-long orbit. These days when the Moon is full at perigee it gets called a “supermoon”, and on Sept. 27 it will be totally eclipsed during the closest supermoon of the entire year. That hasn’t happened since 1982, when The Clash was Rocking the Casbah, times were fast at Ridgemont High, and virtually no one knew what an Ewok was. (Yes, kids, it’s true.)
No, no, no…a thousand times NO: Mars will not become a “second Moon” in the sky on August 27. It won’t this year, it didn’t last year, and it didn’t in the past dozen years since this silly yet strangely perennial cyber-legend (yes I just used the prefix “cyber”) first started circulating on teh interwebz. I don’t know why it keeps rising from the e-dead every year, some years more omnipresently than others, but the bottom line is it simply won’t happen. Not this time, not ever… the Solar System just doesn’t work that way. (And good thing too!)
As the midsummer Sun beats down on the southern mountains of Mars, bringing daytime temperatures soaring up to a balmy 25ºC (77ºF), some of their slopes become darkened with long, rusty stains that may be the result of water seeping out from just below the surface.
The image above, captured by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter on Feb. 20, shows mountain peaks within the 150-km (93-mile) -wide Hale Crater. Made from data acquired in visible and near infrared wavelengths the long stains are very evident, running down steep slopes below the rocky cliffs… but the process that’s responsible for them has yet to be confirmed.