Amateur Estimates Of Venusian Day Using Arecibo Data

July 23, 2023 by Chris Lott 7 Comments

[Nathaniel Fairfield] aka [thandal] was curious about the actual rotation and axis tilt of Venus. He decided to spin up at GitHub Python repository to study the issue further, as one does. The scientific literature shows a wide range of estimates and variations for the planet’s rotation and axis tilt. He wondered if the real answer might be found in a publicly available set of uncalibrated delay-doppler images of Venus. These data were collected by the former Arecibo Observatory in Puerto Rico from 1988 through 2020. [Thanda] observed that the planet’s rotation appears to be speeding up slightly, and furthermore, his estimates of the orbital axis were within 0.01 degrees of the International Astronomical Union’s (IAU) values. [Note: Venus is a bit confusing — one planetary rotation, 243 Earth days, is longer than its year, 225 Earth days].

Estimations of Venusian Orbital Period, [Thandal] Estimates in Green

Aligning and calibrating the raw data was no trivial task. You have to consider the radar’s (Earth’s) position and time, as well as Venus. Complicating the math even more, some times the radar was operated in a bistatic mode, with the Green Bank Telescope in West Virginia being the receiver.

There’s a lot of interesting signal processing going on here. The Doppler-delay data consists of images that are 8091×8092 array of complex values, has to be mapped onto the Venus geoid. Then by using various surface features, one can compare their positions vs time and obtain an estimate of rotational speed and tilt. If these kinds of calculations interest you, be sure to check out [Thandal]’s summary report, and also take note of the poliastro Python astrodynamics library. Why is this important? One reason to better plan future missions.

Hackaday Links: July 31, 2022

July 31, 2022 by Dan Maloney 12 Comments

Don’t look up! As of the time of this writing, there’s a decent chance that a Chinese Long March 5B booster has already completed its uncontrolled return to Earth, hopefully safely. The reentry prediction was continually tweaked over the last week or so, until the consensus closed in on 30 Jul 2022 at 17:08 UTC, give or take an hour either way. That two-hour window makes for a LOT of uncertainty about where the 25-ton piece of space debris will end up. Given the last prediction by The Aerospace Corporation, the likely surface paths cover a lot of open ocean, with only parts of Mexico and South America potentially in the crosshairs, along with parts of Indonesia. It’s expected that most of the material in the massive booster will burn up in the atmosphere, but with the size of the thing, even 20% making it to the ground could be catastrophic, as it nearly was in 2020.

[Update: US Space Command confirms that the booster splashed down in the Indian Ocean region at 16:45 UTC. No word yet on how much debris survived, or if any populated areas were impacted.]

Good news, everyone — thanks to 3D printing, we now know the maximum height of a dive into water that the average human can perform without injury. And it’s surprisingly small — 8 meters for head first, 12 meters if you break the water with your hands first, and 15 meters feet first. Bear in mind this is for the average person; the record for surviving a foot-first dive is almost 60 meters, but that was by a trained diver. Researchers from Cornell came up with these numbers by printing models of human divers in various poses, fitting them with accelerometers, and comparing the readings they got with known figures for deceleration injuries. There was no mention of the maximum survivable belly flop, but based on first-hand anecdotal experience, we’d say it’s not much more than a meter.

Humans have done a lot of spacefaring in the last sixty years or so, but almost all of it has been either in low Earth orbit or as flybys of our neighbors in the Sol system. Sure we’ve landed plenty of probes, but mostly on the Moon, Mars, and a few lucky asteroids. And Venus, which is sometimes easy to forget. We were reminded of that fact by this cool video of the 1982 Soviet landing of Venera 14, one of only a few attempts to land on our so-called sister planet. The video shows the few photographs Venera 14 managed to take before being destroyed by the heat and pressure on Venus, but the real treat is the sound recording the probe managed to make. Venera 14 captured the sounds of its own operations on the Venusian surface, including what sounds like a pneumatic drill being used to sample the regolith. It also captured, as the narrator put it, “the gentle blow of the Venusian wind” — as gentle as ultra-dense carbon dioxide hot enough to melt lead can be, anyway.

Continue reading “Hackaday Links: July 31, 2022” →

Checking Up On Earth’s Sister Planet: NASA’s Upcoming Venus Missions

July 9, 2021 by Maya Posch 36 Comments

Even as we bask in the knowledge that our neighboring planet Mars is currently home to a multitude of still functional landers, a triplet of rovers and with an ever-growing satellite network as well as the first ever flying drone on another planet, our other neighboring planet Venus is truly playing the wallflower, with Japan’s Akatsuki orbiter as the lone active Venusian mission right now.

That is about to change, however, with NASA having selected two new missions that will explore Venus by the end of this decade. The DAVINCI+ and VERITAS missions aim to respectively characterize Venus’ atmosphere and map its surface in unprecedented detail. This should provide us information about possible tectonic activity, as well as details about the Venusian atmosphere which so far have been sorely missing.

Despite Venus being the closest match to our planet Earth, how is it possible that we have been neglecting it for so long, and what can we expect from future missions, including and beyond these two new NASA missions?

Continue reading “Checking Up On Earth’s Sister Planet: NASA’s Upcoming Venus Missions” →

Silicon Carbide Chips Can Go To Hell

May 3, 2021 by Al Williams 75 Comments

IEEE Spectrum had an interesting read about circuits using silicon carbide as a substrate. [Alan Mantooth] and colleagues say that circuits based on this or some other rugged technology will be necessary for missions to Venus, which they liken to hell. That might seem like hyperbole, but at about 460C with an atmosphere full of sulphuric acid, maybe it isn’t such a stretch. When the Soviets sent Venera 13 to Venus, it was able to send data for just over two hours before it was gone. You’d hope 40 years later we could do better.

Silicon carbide is a semiconductor made with an even mix of silicon and carbon. The resulting components can operate for at least a year at 500C. This high-temperature operation has earned them a place in solar energy and other demanding applications. [Alan], with the University of Arkansas along with colleagues from the KTH Royal Insitute of Technology in Stockholm are building test circuits aimed at developing high-temperature radios for use in environments like the one found on Venus.

Continue reading “Silicon Carbide Chips Can Go To Hell” →

Hackaday Links: February 7, 2021

February 7, 2021 by Dan Maloney 14 Comments

What’s that they say about death and taxes? Apparently that maxim doesn’t apply to Flash, at least when it comes to the taxman. As we noted last week, the end of the Adobe Flash era took with it a scheduling and routing app for the railway system in a Chinese city. This time around, it’s the unfortunately acronymed SARS, for South African Revenue Services, having Flash woes. They still have several online tax forms that haven’t been migrated to HTML5, so to keep the revenue flowing they built their own Flash-enabled browser. Taxpayers are free to download and use the browser while SARS works on getting the rest of their forms migrated. It sort of reminds us of those plans the Internal Revenue Service has to ensure tax collection continues after a nuclear apocalypse — death and taxes indeed.

Trouble for Nintendo in the EU? It looks that way, as consumer groups have made the case to EU regulators that Nintendo’s wildly popular Switch consoles are showing unacceptably premature obsolescence with the notorious “Joy-Con drift” issue. The problem, which manifests as players being unable to control a game due to constant movement despite no inputs on the joystick-like controller, requires a repair, one that Nintendo initially only did for free as warranty service for consoles less than a year old. For consoles out of the warranty period, Nintendo was charging €45, which is approximately the same as what a new controller would cost. This didn’t sit well with regulators, and now they’re breathing down Nintendo’s neck. They now offer free repairs for up to two years, but they’re still under the EU microscope. The interesting bit in the linked document is the technical reason for the problem, which is attributed to premature PCB wear — possibly meaning the traces wear away — and inadequate sealing of the Joy-Con mechanism against dust intrusion.

Last year looked as though it was going to be an exciting one with respect to some of our nearest solar and galactic neighbors. For a while there, it looked like the red giant Betelgeuse was going to go supernova, which would have been interesting to watch. And closer to home, there were some signs of life, in the form of phosphine gas, detected in the roiling atmosphere of our sister planet, Venus. Alas, both stories appear not to have panned out. The much-hoped-for (by me) Betelgeuse explosion, which was potentially heralded by a strange off-cycle dimming of the variable star, seems now to be due to its upper atmosphere cooling by several hundred degrees. As for Venus, the phosphine gas that was detected appears actually to have been a false positive triggered by sulfur dioxide. Disappointing results perhaps, but that’s how science is supposed to work.

Amateur radio often gets a bad rap, derided as a hobby for rich old dudes who just like to talk about their medical problems. Some of that is deserved, no doubt, but there’s still a lot of room in the hobby for those interested in advancing the state of the art in radio communications. In this vein, we were pleased to learn about HamSCI, which is short for Ham Radio Science Citizen Investigation. The group takes to heart one of the stated primary missions of amateur radio as the “ontinuation and extension of the amateur’s proven ability to contribute to the advancement of the radio art.” To that end, they’ll be holding HamSCI Workshop 2021, a virtual conference that will be focused on midlatitude ionospheric science. This appears to be a real science conference where both credentialed scientists and amateurs can share ideas. They’ve got a Call for Proposals now, with abstracts due by February 15. The conference itself will be on March 19 and 20, with free admission. The list of invited speakers looks pretty impressive, so if you have any interest in the field, check it out.

And finally, we got a tip this week about a collection of goofy US patents. Everything listed, from the extreme combover to baby bum-print art, is supposedly covered by a patent. We didn’t bother checking Google Patents, but some of these are pretty good for a laugh. We did look at a few, though, and were surprised to learn that the Gerbil Shirt is not a garment for rodents, but a rodent-filled garment for humans.

Hackaday Podcast 086: News Overflow, Formula 1/3 Racer, Standing Up For Rubber Duckies, And Useless Machine Takes A Turn

September 25, 2020 by Mike Szczys No comments

Hackaday editors Elliot Williams and Mike Szczys peruse the world of hacks. There was so much news this week that we lead off the show with a rundown to catch you up. Yet there is still no shortage of hardware hacks, with prosthetic legs for your rubber ducky, a RC cart that channels the spirit of Formula 1, and a project that brings 80’s video conferencing hardware to Zoom. There’s phosphine gas on Venus and unlimited hacking projects inside your guitar. The week wouldn’t be complete without the joy of riffing on the most useless machine concept.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 086: News Overflow, Formula 1/3 Racer, Standing Up For Rubber Duckies, And Useless Machine Takes A Turn” →

Exploring The Clouds Of Venus; It’s Not Fantasy, But It Will Take Specialized Spacecraft

September 21, 2020 by Tom Nardi 23 Comments

By now, you’ve likely heard that scientists have found a potential sign of biological life on Venus. Through a series of radio telescope observations in 2017 and 2019, they were able to confirm the presence of phosphine gas high in the planet’s thick atmosphere. Here on Earth, the only way this gas is produced outside of the laboratory is through microbial processes. The fact that it’s detectable at such high concentrations in the Venusian atmosphere means we either don’t know as much as we thought we did about phosphine, or more tantalizingly, that the spark of life has been found on our nearest planetary neighbor.

To many, the idea that life could survive on Venus is difficult to imagine. While it’s technically the planet most like Earth in terms of size, mass, composition, and proximity to the Sun, the surface of this rocky world is absolutely hellish; with a runaway greenhouse effect producing temperatures in excess of 460 C (840 F). Life, at least as we currently know it, would find no safe haven on the surface of Venus. Even the Soviet Venera landers, sent to the planet in the 1980s, were unable to survive the intense heat and pressure for more than a few hours.

While the surface may largely be outside of our reach, the planet’s exceptionally dense atmosphere is another story entirely. At an altitude of approximately 50 kilometers, conditions inside the Venusian atmosphere are far more forgiving. The atmospheric pressure at this altitude is almost identical to surface-level pressures on Earth, and the average temperature is cool enough that liquid water can form. While the chemical composition of the atmosphere is not breathable by Earthly standards, and the clouds of sulfuric acid aren’t particularly welcoming, it’s certainly not out of the realm of possibility that simple organisms could thrive in this CO2-rich environment. If there really is life on Venus, many speculate it will be found hiding in this relatively benign microcosm high in the clouds.

In short, all the pieces seem to be falling into place. Observations confirm a telltale marker of biological life is in the upper levels of the Venusian atmosphere, and we know from previous studies that this region is arguably one of the most Earth-like environments in the solar system. It’s still far too early to claim we’ve discovered extraterrestrial life, but it’s not hard to see why people are getting so excited.

But this isn’t the first time scientists have turned their gaze towards Earth’s twin. In fact, had things gone differently, NASA might have sent a crew out to Venus after the Apollo program had completed its survey of the Moon. If that mission had launched back in the 1970s, it could have fundamentally reshaped our understanding of the planet; and perhaps even our understanding of humanity’s place in the cosmos.

Continue reading “Exploring The Clouds Of Venus; It’s Not Fantasy, But It Will Take Specialized Spacecraft” →