April 13, 2021 6 min read
The Hubble Space Telescope was launched on April 24, 1990 aboard the Discovery shuttle, and since then, we've been blessed with thousands of jaw-dropping images from every corner of the universe.
Here we're going to showcase what we think are some of the coolest space images ever taken by the Hubble Telescope.
This Hubble image of the Sombrero Galaxy (M104) looks almost unreal. Located 28 million light-years away in the Virgo constellation, the sharpness of this image and the level of detail that we can resolve from such an enormous distance indicates just how powerful the Hubble Telescope truly is.
Just think about how far away this galaxy is for a moment: Traveling at the speed of light, it would take you 28 million years to reach it. Yet Hubble can resolve so much detail that it almost feels like we're hovering right there at the outskirts. Amazing!
We read on HubbleSite.org that:
"The Sombrero lies at the southern edge of the rich Virgo cluster of galaxies and is one of the most massive objects in that group, equivalent to 800 billion suns."
The Sombrero Galaxy is about 50,000 light years across. What this means is that traveling at the speed of light, just to get from one end of the galaxy to the other would take you 50,000 years—roughly 500 human lifetimes. Imagining trying to traverse this distance in a spacecraft of your own, then realizing that this is just one of billions of galaxies in our universe, begins to give you an idea of just how mind-bogglingly massive our universe truly is.
This series of images from the Hubble Telescope absolutely blows my mind every single time I see it. (ViewSpace.org has a cool interactive version of these images that you can play around with. "Hey, where did those 20 minutes just go?!")
HubbleSite.org tells us that "the [red supergiant] star suddenly brightened in January 2002. V838 Mon temporarily became 600,000 times brighter than our Sun."
To simplify the precise mechanism that produced this interstellar phenomenon, basically what happened here was: This red supergiant star brightened dramatically, illuminating its own previously-ejected material.
This picture-perfect spiral galaxy was imaged by the Hubble Space Telescope in 2010. Like many final Hubble images that get released to the public, it's actually not pure visible light that we're seeing here. As explained by NASA, "Wavelengths [of this image] range from ultraviolet light through visible light to near-infrared light."
They also provide the following fun facts about this galaxy:
"Notably missing are pinkish emission nebulae indicative of new star birth. It is likely that the radiation and supersonic winds from fiery, super-hot, young blue stars cleared out the remaining gas (which glows pink), and hence shut down further star formation in the regions in which they were born. NGC 2841 currently has a relatively low star formation rate compared to other spirals that are ablaze with emission nebulae."
This one is a Hubble classic. Located within the Eagle Nebula (M16), the Pillars of Creation "are part of an active star-forming region within the nebula and hide newborn stars in their wispy columns."
Representing another example of Hubble Telescope false-color magic, "The blue colors in the image represent oxygen, red is sulfur, and green represents both nitrogen and hydrogen."
I'm not sure how you guys feel about this, but this is one of those details about astronomy I almost wish I had never learned about. I think I'd prefer to go about my life believing that out there in the universe, there are these richly-colored nebulas filled with deep blues and greens like something out of a watercolor painting. I choose to believe!
Fun fact about the Pillars: They're about five light-years tall. So again, traveling at the speed of light, it would take you five full years to "climb" one of these pillars from bottom to top. Mind-blowing!
Here's a really cool detail about The Helix Nebula: If you look closely at that image, you'll see that right there in the center is the white dwarf star that produced the nebula!
NASA explains the formation mechanism of such a planetary nebula:
"Planetary nebulae are actually the remains of stars that once looked a lot like our sun. These stars spend most of their lives turning hydrogen into helium in massive runaway nuclear fusion reactions in their cores. . . When the hydrogen fuel for the fusion reaction runs out, the star turns to helium for a fuel source, burning it into an even heavier mix of carbon, nitrogen and oxygen. Eventually, the helium will also be exhausted, and the star dies, puffing off its outer gaseous layers and leaving behind the tiny, hot, dense core, called a white dwarf. The white dwarf is about the size of Earth, but has a mass very close to that of the original star; in fact, a teaspoon of a white dwarf would weigh as much as a few elephants!"
Because The Helix Nebula is "only" 650 light-years away, it's about half the size of the full moon in the sky. If that's the case, you might ask, when we look up at the night sky, why don't we see this nebula up there in all its colorful glory? That's because to produce an image such as this, it requires a long exposure from the telescope to gather large amounts of light. Unfortunately our eyes don't work like this—even if you stare up at the same spot in the sky for hours on end.
ViewSpace.org has another cool interactive series of images on The Helix Nebula.
In contrast to The Helix Nebula that we just looked at, the formation mechanism behind The Crab Nebula is very different: This one was formed by a good old-fashioned supernova explosion.
And the supernova explosion that produced it was actually witnessed several hundred years ago by real, living human beings!
"On July 4, in the year 1054 A.D., Chinese astronomers noticed a bright 'guest' star near Tianguan, a star we now call Zeta Tauri in the constellation of the Taurus the Bull. Although the historical records are not precise, the bright new star likely outshone Venus, and for a while was the third-brightest object in the sky, after the sun and moon."
NASA also points out that this supernova explosion was visible in the DAYTIME sky for nearly an entire month! And this despite the fact that the explosion took place 6,500 light years from Earth. Just imagine what it would have looked like if we were located much closer to the star—say, 600 light-years, or even 60 light-years, instead of 6,000. The supernova explosions that produce nebulas such as these are truly devastating events.
Similar to The Pillars of Creation that we saw earlier, what we're seeing here are huge collections of gas in a star-forming region.
NASA explains the various interactions going on here:
"Radiation from hot, young stars has slowly eroded the nebula over millions of years. Ultraviolet light heats the edges of the dark cloud, releasing gas into the relatively empty region of surrounding space. There, additional ultraviolet radiation causes the hydrogen gas to glow, which produces the red halo of light seen around the pillar."
This portion of the nebula that we see here in this Hubble image is about 2.5 light-years tall.
As far as Hubble images go, this one is definitely underrated. Very rarely will you see it make people's lists of "Best Hubble Images."
The reason I selected this one, however, is because it very beautifully showcases the many different colors (and temperatures) of stars out there in the universe: some absolutely enormous and bright blue, others on the smaller side burning a cooler orange. (On that note, check out our educational poster on "The Lives Of Stars")
It's a simple image, but it's one that I really enjoy.
This Hubble image provides us with a perfect top-down view of a spiral galaxy. (Or should I say bottom-up view? Does it really matter in space—and is there one right answer to this question?)
NASA explains that star formation is higher in this galaxy than would otherwise be present. That's because of the gravitational interaction between the larger Whirlpool Galaxy, and its neighbor galaxy NGC 5195. As they write, "The compact galaxy appears to be tugging on the arm, the tidal forces from which trigger new star formation."
HubbleSite.org describes this nebula as "a visual 'fossil record' of the dynamics and late evolution of a dying star."
"Observations suggest the star ejected its mass in a series of pulses at 1,500-year intervals. These convulsions created dust shells, each of which contain as much mass as all of the planets in our solar system combined (still only one percent of the Sun's mass). These concentric shells make a layered, onion-skin structure around the dying star. The view from Hubble is like seeing an onion cut in half, where each skin layer is discernible."
Which of these amazing space pictures from the Hubble Telescope was your favorite? Are there any great ones that you think we should have included here?
Can't pick a favorite? You don't have to! Check out our Hubble Space Telescope's "Greatest Hits", which features 88 stunning images from outer space!
April 16, 2021 6 min read