What Isaac Roberts Saw Without A Space Telescope

Space telescopes are all the rage, and rightfully so. The images they take are spectacular, and they’ve greatly increased what we know about the universe. Surely, any picture taken of, say, the Andromeda galaxy before space telescopes would be little more than a smudge compared to modern photos, right? Maybe not.

One of the most famous pictures of our galactic neighbor was taken in — no kidding — 1888. The astronomer/photographer was Isaac Roberts, a Welsh engineer with a keen interest in astrophotography. Around 1878, he began using a 180 mm refracting telescope for observations, and in 1883, he began taking photographs.

He was so pleased with the results that he ordered a reflecting telescope with a 510 mm first-surface mirror and built an observatory around it in 1885. Photography and optics back then weren’t what they are now, so adding more mirrors to the setup made it more challenging to take pictures. Roberts instead mounted the photographic plates directly at the prime focus of the mirror.

Andromeda

This image, captured with the NASA/ESA Hubble Space Telescope, is the largest and sharpest image ever taken of the Andromeda galaxy — otherwise known as M31. This is a cropped version of the full image and has 1.5 billion pixels. You would need more than 600 HD television screens to display the whole image. It is the biggest Hubble image ever released and shows over 100 million stars and thousands of star clusters embedded in a section of the galaxy’s pancake-shaped disc stretching across over 40 000 light-years. This image is too large to be easily displayed at full resolution.

Because it took hours to capture good images, he developed techniques to keep the camera moving in sync with the telescope to track objects in the night sky. On December 29th, 1888 he used his 510 mm scope to take a long exposure of Andromeda (or M31, if you prefer). His photos showed the galaxy had a spiral structure, which was news in 1888.

Of course, it’s not as good as the Hubble’s shots. In all fairness, though, the Hubble’s is hard to appreciate without the interactive zoom tool. And 100 years of technological progress separate the two.

Roberts also invented a machine that could engrave stellar positions on copper plates. The Science Museum in London has the telescope in its collection.

Your Turn

Roberts did a great job with very modest equipment. These days, at least half of astrophotography is in post-processing, which you can learn. Want time on a big telescope? Consider taking an online class. You might not match the James Webb or the Hubble, but neither did Roberts, yet we still look at his plates with admiration.

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Hackaday Links: June 8, 2025

When purchasing high-end gear, it’s not uncommon for manufacturers to include a little swag in the box. It makes the customer feel a bit better about the amount of money that just left their wallet, and it’s a great way for the manufacturer to build some brand loyalty and perhaps even get their logo out into the public. What’s not expected, though, is for the swag to be the only thing in the box. That’s what a Redditor reported after a recent purchase of an Nvidia GeForce RTX 5090, a GPU that lists for $1,999 but is so in-demand that it’s unobtainium at anything south of $2,600. When the factory-sealed box was opened, the Redditor found it stuffed with two cheap backpacks instead of the card. To add insult to injury, the bags didn’t even sport an Nvidia logo.

The purchase was made at a Micro Center in Santa Clara, California, and an investigation by the store revealed 31 other cards had been similarly tampered with, although no word on what they contained in lieu of the intended hardware. The fact that the boxes were apparently sealed at the factory with authentic anti-tamper tape seems to suggest the substitutions happened very high in the supply chain, possibly even at the end of the assembly line. It’s a little hard to imagine how a factory worker was able to smuggle 32 high-end graphics cards out of the building, so maybe the crime occurred lower down in the supply chain by someone with access to factory seals. Either way, the thief or thieves ended up with almost $100,000 worth of hardware, and with that kind of incentive, this kind of thing will likely happen again. Keep your wits about you when you make a purchase like this.

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Vera Rubin: Shedding Light On Dark Matter

Vera sat hunched in the alcove at Kitt Peak observatory, poring over punch cards. The data was the same as it had been at Lowell, at Palomar, and every other telescope she’d peered through in her feverish race to collect the orbital velocities of stars in Andromeda. Although the data was perfectly clear, the problem it posed was puzzling. If the stars at the edges of spiral galaxy were moving as fast as the ones in the center, but the pull of gravity was weaker, how did they keep from flying off? The only possible answer was that Andromeda contained some kind of unseen matter and this invisible stuff was keeping the galaxy together.

Though the idea seemed radical, it wasn’t an entirely new one. In 1933, Swiss astronomer Fritz Zwicky made an amazing discovery that was bound to bring him fame and fortune. While trying to calculate the total mass of the galaxies that make up the Coma Cluster, he found that the mass calculation based on galaxy speed was about ten times higher than the one based on total light output. With this data as proof, he proposed that much of the universe is made of something undetectable, but undeniably real. He dubbed it Dunkle Materie: Dark Matter.

But Zwicky was known to regularly bad mouth his colleagues and other astronomers in general. As a result, his wild theory was poorly received and subsequently shelved until the 1970s, when astronomer Vera Rubin made the same discovery using a high-powered spectrograph. Her findings seemed to provide solid evidence of the controversial theory Zwicky had offered forty years earlier.

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