telescope

85 Articles

All The Stars, All The Time

June 27, 2025 by 5 Comments

Some of the largest objects in the night sky to view through a telescope are galaxies and supernova remnants, often many times larger in size than the moon but generally much less bright. Even so, they take up a mere fraction of the night sky, with even the largest planets in our solar system only taking up a few arcseconds and stars appearing as point sources. There are more things to look at in the sky than there are telescopes, regardless of size, so it might almost seem like an impossible task to see everything. Yet that’s what this new telescope in Chile aims to do.

The Vera C. Rubin Observatory plans to image the entire sky every few nights over a period lasting for ten years. This will allow astronomers to see the many ways the cosmos change with more data than has ever been available to them. The field of view of the telescope is about 3.5 degrees in diameter, so it needs to move often and quickly in order to take these images. At first glance the telescope looks like any other large, visible light telescope on the tops of the Andes, Mauna Kea, or the Canary Islands. But it has a huge motor to move it, as well as a large sensor which generates a 3200-megapixel image every 30 seconds.

In many ways the observatory’s telescope an imaging technology is only the first part of the project. A number of machine learning algorithms and other software solutions have been created to help astronomers sift through the huge amount of data the telescope is generating and find new irregularities in the data, from asteroids to supernovae. First light for the telescope was this month, June 2025, and some of the first images can be seen here. There have been a number of interesting astronomical observations underway lately even excluding the JWST. Take a look at this solar telescope which uses a new algorithm to take much higher resolution images than ever before.

Build Your Own Telescope The Modern Way

June 19, 2025 by 37 Comments

When we were kids, it was a rite of passage to read the newly arrived Edmund catalog and dream of building our own telescope. One of our friends lived near a University, and they even had a summer program that would help you measure your mirrors and ensure you had a successful build. But most of us never ground mirrors from glass blanks and did all the other arcane steps required to make a working telescope. However, [La3emedimension] wants to tempt us again with a 3D-printable telescope kit.

Before you fire up the 3D printer, be aware that PLA is not recommended, and, of course, you are going to need some extra parts. There is supposed to be a README with a bill of parts, but we didn’t see it. However, there is a support page in French and a Discord server, so we have no doubt it can be found.

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Adaptive Optics Take Clearest Pictures Of The Sun Yet

June 1, 2025 by 9 Comments

It’s sometimes easy to forget that the light in the sky is an actual star. With how reliable it is and how busy we tend to be as humans, we can take that incredible fact and stow it away and largely go on with our lives unaffected. But our star is the thing that gives everything on the planet life and energy and is important to understand. Humans don’t have a full understanding of it either; there are several unsolved mysteries in physics which revolve around the sun, the most famous of which is the coronal heating problem. To help further our understanding a number of scientific instruments have been devised to probe deeper into it, and this adaptive optics system just captures some of the most impressive images of it yet.

Adaptive optics systems are installed in terrestrial telescopes to help mitigate the distortion of incoming light caused by Earth’s atmosphere. They generally involve using a reference source to measure these distortions, and then make changes to the way the telescope gathers light, in this case by making rapid, slight changes to the telescope’s mirror. This system has been installed on the Goode Solar Telescope in California and has allowed scientists to view various solar phenomena with unprecedented clarity.

The adaptive optics system here has allowed researchers to improve the resolution from the 1000 km resolution of other solar telescopes down to nearly the theoretical limit of this telescope—63 km. With this kind of resolution the researchers hope that this clarity will help shine some light on some of the sun’s ongoing mysteries. Adaptive optics systems like this aren’t just used on terrestrial telescopes, either. This demonstration shows how the adaptive optics system works on the James Webb Space Telescope.

Thanks to [iliis] for the tip!

Two telescopes looking into the night sky.

Making A Backyard Observatory Complete With Retractable Roof

May 24, 2025 by 16 Comments

Here’s one for our astronomy geeks. Our hacker [arrow] has made their own observatory!

This particular video is a bit over ten minutes long and is basically a montage; there is no narration or explanation given, but you can watch clear progress being made and the ultimate success of the backyard facility.

Obviously the coolest thing about this building is that the roof can be moved, but those telescope mounts look pretty sexy too. About halfway through the video the concrete slab that was supporting one metal mounting pole gets torn up so that two replacements can be installed, thereby doubling the capacity of the observatory from one telescope to two.

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Thermal Monocular Brings The Heat At 10X

May 13, 2025 by 5 Comments

[Project 326] is following up on his thermal microscope with a thermal telescope or, more precisely, a thermal monocular. In fact, many of the components and lenses in this project are the same as those in the microscope, so you could cannibalize that project for this one, if you wanted.

During the microscope project, [Project 326] noted that first-surface mirrors reflect IR as well as visible light. The plan was to make a Newtonian telescope for IR instead of light. While the resulting telescope worked with visible light, the diffraction limit prevented it from working for its intended purpose.

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Make Your Own Telescope, Right Down To The Glass

May 1, 2025 by 14 Comments

Telescopes are great tools for observing the heavens, or even surrounding landscapes if you have the right vantage point. You don’t have to be a professional to build one though; you can make all kinds of telescopes as an amateur, as this guide from the Springfield Telescope Makers demonstrates.

The guide is remarkably deep and rich; no surprise given that the Springfield Telescope Makers club dates back to the early 20th century. It starts out with the basics—how to select a telescope, and how to decide whether to make or buy your desired instrument. It also explains in good detail why you might want to start with a simple Newtonian reflector setup on Dobsonian mounts if you’re crafting your first telescope, in no small part because mirrors are so much easier to craft than lenses for the amateur. From there, the guide gets into the nitty gritty of mirror production, right down to grinding and polishing techniques, as well as how to test your optical components and assemble your final telescope.

It’s hard to imagine a better place to start than here as an amateur telescope builder. It’s a rich mine of experience and practical advice that should give you the best possible chance of success. You might also like to peruse some of the other telescope projects we’ve covered previously. And, if you succeed, you can always tell us of your tales on the tipsline!

Dwingeloo telescope with sun shining through

Dwingeloo To Venus: Report Of A Successful Bounce

March 28, 2025 by 14 Comments

Radio waves travel fast, and they can bounce, too. If you are able to operate a 25-meter dish, a transmitter, a solid software-defined radio, and an atomic clock, the answer is: yes, they can go all the way to Venus and back. On March 22, 2025, the Dwingeloo telescope in the Netherlands successfully pulled off an Earth-Venus-Earth (EVE) bounce, making them the second group of amateurs ever to do so. The full breakdown of this feat is available in their write-up here.

Bouncing signals off planets isn’t new. NASA has been at it since the 1960s – but amateur radio astronomers have far fewer toys to play with. Before Dwingeloo’s success, AMSAT-DL achieved the only known amateur EVE bounce back in 2009. This time, the Dwingeloo team transmitted a 278-second tone at 1299.5 MHz, with the round trip to Venus taking about 280 seconds. Stockert’s radio telescope in Germany also picked up the returning echo, stronger than Dwingeloo’s own, due to its more sensitive receiving setup.

Post-processing wasn’t easy either. Doppler shift corrections had to be applied, and the received signal was split into 1 Hz frequency bins. The resulting detections clocked in at 5.4 sigma for Dwingeloo alone, 8.5 sigma for Stockert’s recording, and 9.2 sigma when combining both datasets. A clear signal, loud and proud, straight from Venus’ surface.

The experiment was cut short when Dwingeloo’s transmitter started failing after four successful bounces. More complex signal modulations will have to wait for the next Venus conjunction in October 2026. Until then, you can read our previously published article on achievements of the Dwingeloo telescope.