It has been 18 years since Earthlings have been able to spy five planets in their skies, together and in order from Sun outward, but it’s possible now through the end of June. Want to take a look? Maybe you should. Yes, get up early — 30 to 45 minutes ahead of sunrise — find a spot where you can see the southern sky, and sweep your gaze from the east to the south.
Given clear skies low to the eastern horizon, look for a tiny star-like dot. If you’re lucky, you’ll have spotted planet Mercury, the most elusive of the worlds you’ll see due to its size and proximity to Sun. Moving westward, next comes Venus. You’ll have no trouble spotting Earth’s overheated sister as it will shine brilliantly even in early twilight.
Skipping Earth (it doesn’t count because you’re standing on it) Mars is next in line. Look for a little reddish light not far from brighter Jupiter. Moving across a bigger gap and looking south, we finally reach Saturn, the Lord of the Rings. The ringed world will appear as a slightly golden star.
Binoculars will help, especially in finding tiny Mercury, but may also allow users to see Jupiter’s four Galilean Moons. A little visual aid may also help in confirming it’s Saturn that has been spotted — if the rings aren’t distinct, the planet will appear as a bright oval and not like a starry speck.
The planets will be joined by Earth’s Moon at various points along their arc, changing placement nightly from about June 18 — 28. A beautiful arrangement will occur on June 24 when the then-crescent Moon will float between Venus and Mars. Around the 28th, Moon will have drifted out of the arc entering its New (dark) phase.
At the end of June, Mercury will slip too close to Sun for it to be seen by casual observers, ending the celestial gathering. The four other planets, however, will remain in their arc though their relative positions will shift nightly and almost imperceptibly, until they no longer form a visual chain.
The five-planet dance was last seen in 2004 and it won’t happen again until 2040. Maybe you’ll be on your way to or from work. Perhaps the dog needs walking. You may even think it’s worth getting out of bed early on a clear, cool June morning so you can tell everyone you saw five planets all together. Whatever puts you under a clear starry sky, look up and enjoy our wonderful universe.
February 2022 — News is the remains of the scuttled ship Endeavour, commanded by Lt. James Cook, have been discovered in Newport Harbor, Rhode Island, where they lay for more than 200 years. The ship sailed to Tahiti to observe the June 3, 1769 transit of Venus. Endeavour was, of course, involved in far broader explorations of the South Pacific, but the news of her discovery reminded me of my own experience: the June 5, 2015 transit of Venus — observed 246 years after Cook — from Hiram at a public event we hosted.
Recalling that day, the afternoon was cloudy and rainy and I thought we would miss out. But mere minutes before the silhouette of Venus was to appear on Sun’s face mists faded, clouds parted, and Sun shined brightly. I quickly finished setting up the telescopes, peered through the eyepiece to focus, and saw the same “black drop” phenomenon Cook sketched. My camera was set up too late (due to the aforementioned weather) to record the “black drop” for later sharing.
We hosted visitors at our mobile telescope site — the former location of Hiram Elementary School — until Sun sank below the treeline to our west, the transit still in progress. In the end more than 100 (estimated count lost) men, women, and children saw that big black dot moving across the sun. It was a lovely experience.
A transit of Venus is the passage of the planet across the face of our Sun as seen from Earth. Transits of Venus are rare; they come in pairs, 8 years apart, separated by approximately 120 years. Our next opportunity comes in December 2117. See you then?
An international team of astronomers today announced the discovery of a rare molecule — phosphine — in the clouds of Venus. On Earth, this gas is only made industrially or by microbes that thrive in oxygen-free environments. Astronomers have speculated for decades that high clouds on Venus could offer a home for microbes — floating free of the scorching surface but needing to tolerate very high acidity. The detection of phosphine could point to such extra-terrestrial “aerial” life. Confirming the presence of life, however, will require much more work.
“When we got the first hints of phosphine in Venus’s spectrum, it was a shock!”, says team leader Jane Greaves of Cardiff University in the UK, who first spotted signs of phosphine in observations from the James Clerk Maxwell Telescope (JCMT), operated by the East Asian Observatory, in Hawaiʻi. Confirming their discovery required using 45 antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, a more sensitive telescope in which the European Southern Observatory (ESO) is a partner. Both facilities observed Venus at a wavelength of about 1 millimeter, much longer than the human eye can see — only telescopes at high altitude can detect it effectively.
The international team, which includes researchers from the UK, US and Japan, estimates that phosphine exists in Venus’s clouds at a small concentration, only about twenty molecules in every billion. Following their observations, they ran calculations to see whether these amounts could come from natural non-biological processes on the planet. Some ideas included sunlight, minerals blown upwards from the surface, volcanoes, or lightning, but none of these could make anywhere near enough of it. These non-biological sources were found to make at most one ten thousandth of the amount of phosphine that the telescopes saw.
To create the observed quantity of phosphine (which consists of hydrogen and phosphorus) on Venus, terrestrial organisms would only need to work at about 10% of their maximum productivity, according to the team. Earth bacteria are known to make phosphine: they take up phosphate from minerals or biological material, add hydrogen, and ultimately expel phosphine. Any organisms on Venus will probably be very different to their Earth cousins, but they too could be the source of phosphine in the atmosphere.
While the discovery of phosphine in Venus’s clouds came as a surprise, the researchers are confident in their detection. “To our great relief, the conditions were good at ALMA for follow-up observations while Venus was at a suitable angle to Earth. Processing the data was tricky, though, as ALMA isn’t usually looking for very subtle effects in very bright objects like Venus,” says team member Anita Richards of the UK ALMA Regional Centre and the University of Manchester. “In the end, we found that both observatories had seen the same thing — faint absorption at the right wavelength to be phosphine gas, where the molecules are backlit by the warmer clouds below,” adds Greaves, who led the study published today in Nature Astronomy.
Another team member, Clara Sousa Silva of the Massachusetts Institute of Technology in the US, has investigated phosphine as a “biosignature” gas of non-oxygen-using life on planets around other stars, because normal chemistry makes so little of it. She comments: “Finding phosphine on Venus was an unexpected bonus! The discovery raises many questions, such as how any organisms could survive. On Earth, some microbes can cope with up to about 5% of acid in their environment — but the clouds of Venus are almost entirely made of acid.”
The team believes their discovery is significant because they can rule out many alternative ways to make phosphine, but they acknowledge that confirming the presence of “life” needs a lot more work. Although the high clouds of Venus have temperatures up to a pleasant 30 degrees Celsius, they are incredibly acidic — around 90% sulfuric acid — posing major issues for any microbes trying to survive there.
ESO astronomer and ALMA European Operations Manager Leonardo Testi, who did not participate in the new study, says: “The non-biological production of phosphine on Venus is excluded by our current understanding of phosphine chemistry in rocky planets’ atmospheres. Confirming the existence of life on Venus’s atmosphere would be a major breakthrough for astrobiology; thus, it is essential to follow-up on this exciting result with theoretical and observational studies to exclude the possibility that phosphine on rocky planets may also have a chemical origin different than on Earth.”
More observations of Venus and of rocky planets outside our Solar System, including with ESO’s forthcoming Extremely Large Telescope, may help gather clues on how phosphine can originate on them and contribute to the search for signs of life beyond Earth.
On Monday, May 9 solar observers in North America will be able to see the silhouette of planet Mercury as it passes between Earth and our Sun. The event, called a transit, is relatively rare — though not so rare as a transit of Venus — and may cause interest in viewing the Sun. WARNING: Looking at the Sun, especially through optical instruments, requires extreme caution! Permanent vision damage can result if proper precautions are not taken! Click here for a good article on safely observing the Sun.
At present we DO NOT plan to open Stephens Observatory for the transit but if plans change, the announcement will be made here — check back later. If conditions are clear, we hope to post images made via telescope at a remote location.
Tiny planet Mercury will appear as a correspondingly tiny black dot against the Sun’s brilliant disk. If any sunspots are present on Sol’s face, compare them with Mercury: the planet will be distinctly round and noticeably darker than sunspots, and from minute to minute it will move — sunspot motion takes days!
Viewed from Earth, transits occur when one of the inner planets crosses the line of sight between our world and the Sun; only Venus and Mercury are ever able to do that. A transit, then, is a bit like a solar eclipse only viewed at a greater distance and blocking only a small amount of the Sun’s light.
Transits would occur more often but for the fact that the orbits of Mercury and Venus are “tipped” so that they do not align along the same plane as Earth’s path. Only when the planets are in the right position where the line of sight passes straight through to the Sun do we see transits and with Mercury, that happens only about 13 times per century. After May 9, the next transits of Mercury will take place in November 2019, November 2032, and November 2049. The most recent transit of Venus took place in June 2012 and will not be seen again until December 2117.
Monday’s transit of Mercury will take place over several hours. For us in Northern Ohio, the transit begins at about 7:12 AM Eastern Daylight Time with the Sun low in the east. Midpoint of Mercury’s passage will be at 10:57 AM, and the transit ends at 2:42 PM.
Cloudy skies? Don’t have proper gear to view the Sun? Fret not! There will be “live” webcasts of the event from various sources during Mercury’s passage. Use your favorite web search engine to find good sources and check for a planned broadcast via NASA TV. NASA will stream a live program on NASA TV and the agency’s Facebook page from 10:30 to 11:30 AM — an informal roundtable during which experts representing planetary, heliophysics and astrophysics will discuss the science behind the Mercury transit. Viewers can ask questions via Facebook and Twitter using #AskNASA.
Over recent weeks we have watched as several planets have appeared close together in our morning sky — when clear, that is — and even seen them shift their positions as the days passed! Beginning this frigid week and continuing into mid-February, five of Earth’s Solar System siblings will be visible, spanning the southern sky. This is the first time since 2005 that this planetary lineup has occurred. If we get a break in morning cloud cover go out, just before dawn’s early light, and look for the planetary parade. Little Mercury will be the hardest to spot being both dim and close to the horizon. Venus and Jupiter will be easy as they are the brightest of the bunch. Golden Saturn and finally reddish Mars should also be easy to find though Mars isn’t a standout. The gathering will occur again late this summer and in the evening sky. The planets aren’t really very much closer together in space during this time. The chart below illustrates the current relative positions of the planets; it’s our point of view from Earth that makes creates the scene: something like watching racers on a race track, appearing closer and farther apart as they run laps in their concentric lanes.
Let’s hope for clear skies the evening of June 30 when the ongoing conjunction of Jupiter and Venus gets really cozy! Tuesday evening will see the two planets sharing a space only 1/3-degree apart in our sky; they will look like a brilliant double star. After Tuesday’s encounter, the planets will drift slowly apart night-by-night but will remain a beautiful sight in twilight. Chart courtesy Sky & Telescope – SkyAndTelescope.com