Comet P/Halley as seen on its last inner solar system passage on March 8th, 1986. (Credit: W. Liller/NASA GSFC/ International Halley Watch Large Scale Phenomena Network).
An interesting and largely unknown tale of ancient astronomy recently came our way while reading author and astrophysicist Mario Livio’s blog. The story involves the passage of the most famous of all comets.
It’s fascinating to consider ancient knowledge of the skies. While our knowledge of ancient astronomy is often sparse, we know that cultures lived and perished by carefully monitoring the passage of the heavens. A heliacal rising of Sirius might coincide with the impending flooding of the life-giving waters of the Nile, or the tracking of the solstices and equinoxes might mark the start of the seasons.
To the ancients, comets were “hairy stars” which appeared unpredictably in the sky. We generally attribute the first realization that comets are periodic to Sir Edmond Halley, who successfully utilized Newton’s laws of gravity and Kepler’s laws of planetary motion to predict the return of Halley’s Comet in 1758. Such a prediction was a vindication of science.
But an interesting tale comes to us from the 1st century CE that Rabbi & Jewish Scholar Yehoshua Ben Hananiah may have known something of “a star that appears every 70 years.” The tale, as told in the Horayoth (rulings) of the Talmud and described in Mr. Livio’s blog is intriguing:
Rabbi Gamliel and Rabbi Yehoshua went together on a voyage at sea. Rabbi Gamliel carried a supply of bread. Rabbi Yehoshua carried a similar amount of bread and in addition a reserve of flour. At sea, they used up the entire supply of bread and had to utilize Rabbi Yehoshua’s flour reserve. Rabbi Gamliel then asked Rabbi Yehoshua: “Did you know that this trip would be longer than usual, when you decided to carry this flour reserve?” Rabbi Yehoshua answered: “There is a star that appears every 70 years and induces navigation errors. I thought it might appear and cause us to go astray.”
The Rabbi’s assertion is a fascinating one. There aren’t a whole lot of astronomical phenomena on 70 cycles that would have been noticeable to ancient astronomers. With an orbital period of 75.3 years, Halley’s Comet seems to fit the bill the best. The earliest confirmed description of Halley’s comes from Chinese astronomers during its 240 BCE passage. Later subsequent passages of the comet through the inner solar system were noted by the Babylonians in 164 & 87 BCE.
Of course, there’s no further evidence that ancient scholars identified those passages as the same comet. Some great comets such as Hale-Bopp seen in 1997 and this year’s anticipated Comet C/2012 S1 ISON are on orbits spanning thousands of years that outlast most Earthly civilizations.
Mr. Livio also notes that historical knowledge of ancient apparitions of Halley’s may have been accessible to the Great Knesset scholars during the Babylonian exile of the 6th century BCE.
One of the chief objections raised to the Halley hypothesis is the circumstances of the appearance of Halley’s Comet in the Rabbi’s lifetime. Remember, most folks didn’t live for 70 years in the 1st century. Any tales of a periodic comet would have been handed down by generations. You would be lucky to see Halley’s Comet once in your lifetime. Plus, not all apparitions of Halley’s Comet are favorable. For example, Halley’s was bright enough to induce “comet hysteria” with the public in 1910. In contrast, few northern hemisphere members of the general public got a good view of it during its 1986 passage.
Medieval woodcut depicting the supposed destructive influence of a 4th century comet. (Credit: Stanilaus Lubienietski’s Theatrum Cometicum, Amsterdam 1668).
Halley’s Comet was visible on and around January 25th, 66 CE during the Rabbi’s lifetime. However, the Rabbi would have been in his 20’s and have been a student (and not yet a Rabbi) himself. One can imagine that if he was fearful of a “false star” leading them astray, he must’ve known that the 70 year period was just about neigh.
The 66 CE apparition of Halley’s Comet would have appeared around the time of the Jewish Rebellion and just four years before the destruction of the Second Temple in Jerusalem by the Romans in 70 CE.
One other possible astronomical culprit has been cited over the years. The classic variable star Mira (Omicron Ceti) currently has a 332 day cycle which ranges from magnitude +3.5 to below naked eye visibility at +8.6 to +10.1. The variability of Mira was first discovered by astronomer David Fabricius on August 3rd 1596. There are suggestions that ancient Chinese and Babylonian astronomers may have known of this “vanishing star”.
The variable star Mira as imaged by the Hubble Space Telescope. (Credit: NASA/STScl/Margarita Karovska at the Harvard-Smithsonian Center for Astrophysics).
Mira is expected to reach maximum for 2013 from July 21st to 31st.
Not all maxima for Mira are of equal brightness. Mira can peak anywhere from magnitude +2.0 to +4.9 (a 15-fold difference) and there’s evidence to suggest it may have been brighter in the past. Astronomer Philippe Veron noted in 1982 that a larger oscillation period of 60 years for the peak maxima of Mira falls just a decade short of Rabbi Yehoshua’s mention of an errant star.
Whatever the case, its fascinating to consider what celestial object might’ve been referred to, and how many other astronomical tales might be awaiting discovery in ancient texts. We’ve got lots of comets to ponder this year as Comet PanSTARRS, Lemmon, and ISON grace our skies in 2013. Halley’s will make its next visit to the inner solar system in 2061. I’ll open it up to you, the astute Universe Today reading public; was the Rabbi’s Star a comet, a variable star, a meteor storm, or none of the above?
Halley’s Comet as seen from latitude 30 north on the morning of July 31st, 2061. (Created by the author using Starry Night software).
-Dr. Mario Livio blogs at A Curious Mind. Be sure to check out his new bookBrilliant Blunders: From Darwin to Einstein – Colossal Mistakes by Great Scientists That Changed Our Understanding of Life in the Universe out on May 14th!
“No scientific discovery is named after its discoverer,” – Stigler/Merton.
Edwin Hubble’s contributions to astronomy earned him the honor of having his name bestowed upon arguably the most famous space telescope (the Hubble Space Telescope, HST). Contributions that are often attributed to him include the discovery of the extragalactic scale (there exist countless other galaxies beyond the Milky Way), the expanding Universe (the Hubble constant), and a galaxy classification system (the Hubble Tuning Fork). However, certain astronomers are questioning Hubble’s pre-eminence in those topics, and if all the credit is warranted.
“[The above mentioned] discoveries … are well-known … and most astronomers would associate them solely with Edwin Hubble; yet this is a gross oversimplification. Astronomers and historians are beginning to revise that standard story and bring a more nuanced version to the public’s attention,” said NASA scientist Michael J. Way, who just published a new study entitled “Dismantling Hubble’s Legacy?”
Has history clouded our view of Hubble the man? Or are his contributions seminal to where we are today in astronomy?
Assigning credit for a discovery is not always straightforward, and Way 2013 notes, “How credit is awarded for a discovery is often a complex issue and should not be oversimplified – yet this happens time and again. Another well-known example in this field is the discovery of the Cosmic Microwave Background.” Indeed, controversy surrounds the discovery of the Universe’s accelerated expansion, which merely occurred in the late 1990s. Conversely, the discoveries attributed to Hubble transpired during the ~1920s.
The Hubble Space Telescope (image credit: NASA, tweaked by D. Majaess).
Prior to commencing this discussion, it’s emphasized that Hubble cannot defend his contribution since he died long ago (1889-1953). Moreover, we can certainly highlight the efforts of other individuals whose seminal contributions were overlooked without mitigating Hubble’s pertinence. The first topic discussed here is the discovery of the extragalactic scale. Prior to the 1920s it was unclear whether the Milky Way galaxy and the Universe were synonymous. In other words, was the Milky Way merely one among countless other galaxies?
Astronomers H. Shapley and H. Curtis argued the topic in the famed Island Universe debate (1920). Curtis believed in the extragalactic Universe, whereas Shapley took the opposing view (see also Trimble 1995 for a review). In the present author’s opinion, Hubble’s contributions helped end that debate a few years later and changed the course of astronomy, namely since he provided evidence of an extragalactic Universe using a distance indicator that was acknowledged as being reliable. Hubble used stars called Cepheid variables to help ascertain that M31 and NGC 6822 were more distant than the estimated size of the Milky Way, which in concert with their deduced size, implied they were galaxies. Incidentally, Hubble’s distances, and those of others, were not as reliable as believed (e.g., Fernie 1969, Peacock 2013). Peacock 2013 provides an interesting comparison between distance estimates cited by Hubble and Lundmark with present values, which reveals that both authors published distances that were flawed in some manner. Having said that, present-day estimates are themselves debated.
Hubble’s evidence helped convince even certain staunch opponents of the extragalactic interpretation such as Shapley, who upon receiving news from Hubble concerning his new findings remarked (1924), “Here is the letter that has destroyed my universe.” Way 2013 likewise notes that, “The issue [concerning the extragalactic scale] was effectively settled by two papers from Hubble in 1925 in which he derived distances from Cepheid variables found in M31 and M33 (Hubble 1925a) of 930,000 light years and in NGC 6822 (Hubble 1925c) of 700,000 light years.”
However, as table 1 from Way 2013 indicates (shown below), there were numerous astronomers who published distances that implied there were galaxies beyond the Milky Way. Astronomer Ian Steer, who helps maintain the NASA/IPAC Extragalactic Database of Redshift-Independent Distances (NED-D), has also compiled a list of 290 distances to galaxies published before 1930. Way 2013 added that, “Many important contributions to this story have been forgotten and most textbooks in astronomy today, if they discuss the “Island Universe” confirmation at all, bestow 100% of the credit on Hubble with scant attention to the earlier observations that clearly supported his measurements.”
Thus Hubble did not discover the extragalactic scale, but his work helped convince a broad array of astronomers of the Universe’s enormity. However, by comparison to present-day estimates, Hubble’s distances are too short owing partly to the existing Cepheid calibration he utilized (Fernie 1969, Peacock 2013 also notes that Hubble’s distances were flawed for other reasons). That offset permeated into certain determinations of the expansion rate of the Universe (the Hubble constant), making the estimate nearly an order of magnitude too large, and the implied age for the Universe too small.
Way 2013 notes, “Table 1 lists all of the main distance estimates to spiral nebulae (known to this author) from the late 1800s until 1930 when standard candles began to be found in spiral nebulae [galaxies].” (image credit: Way 2013/arXiv).Hubble’s accreditation as the discoverer of the expanding Universe (the Hubble constant) has generated considerable discussion, which is ultimately tied to the discovery of a relationship between a galaxy’s velocity and its distance. An accusation even surfaced that Hubble may have censored the publication of another scientist to retain his pre-eminence. That accusation has since been refuted, but provides the reader an indication of the tone of the debate (see Livio 2012 (Nature), and references therein).
Hubble published his findings on the velocity-distance relation in 1929, under the unambiguous title, “A Relation Between Distance and Radial Velocity Among Extra-Galactic Nebulae”. Hubble 1929 states at the outset that other investigations have sought, “a correlation between apparent radial velocities and distances, but so far the results have not been convincing.” The key word being convincing, clearly a subjective term, but which Hubble believes is the principal impetus behind his new effort. In Lundmark 1924, where a velocity versus distance diagram is plotted for galaxies (see below), that author remarks that, “Plotting the radial velocities against these relative distances, we find that there may be a relation between the two quantities, although not a very definite one.” However, Hubble 1929 also makes reference to a study by Lundmark 1925, where Lundmark underscores that, “A rather definite correlation is shown between apparent dimensions and radial velocity, in the sense that the smaller and presumably more distant spirals have the higher space velocity.”
Hubble 1929 provides a velocity-distance diagram (featured below) and also notes that, “the data indicate a linear correlation between distances and velocities”. However, Hubble 1929 explicitly cautioned that, “New data to be expected in the near future may modify the significance of the present investigation, or, if confirmatory, will lead to a solution having many times the weight. For this reason it is thought premature to discuss in detail the obvious consequences of the present results … the linear relation found in the present discussion is a first approximation representing a restricted range in distance.” Hubble implied that additional effort was required to acquire observational data and place the relation on firm (convincing) footing, which would appear in Hubble and Humason 1931. Perhaps that may partly explain, in concert with the natural tendency of most humans to desire recognition and fame, why Hubble subsequently tried to retain credit for the establishment of the velocity-distance relation.
Hubble 1929 conveyed that he was aware of prior (but unconvincing to him) investigations on the topic of the velocity-distance relation. That is further confirmed by van den Bergh 2011, who cites the following pertinent quote recounted by Hubble’s assistant (Humason) for an oral history project, “The velocity-distance relationship started after one of the IAU meetings, I think it was in Holland [1928]. And Dr. Hubble came home rather excited about the fact that two or three scientists over there, astronomers, had suggested that the fainter the nebulae were, the more distant they were and the larger the red shifts would be. And he talked to me and asked if I would try and check that out.”
The velocities of galaxies plotted as a function of their distance, from Lundmark 1924 (left) and Hubble 1929 (right). Note the separate scales on the x-axis. Peacock 2013 demonstrates that distances cited by both authors were ultimately flawed, and problems (albeit less acute) likewise exist with modern distances (image credit: Lundmark/MNRAS/Hubble/PNAS, assembled by D. Majaess).
Hubble 1929 elaborated that, “The outstanding feature, however, is the possibility that the velocity-distance relation may represent the de Sitter effect, and hence that numerical data may be introduced into discussions of the general curvature of space.” de Sitter had proposed a model for the Universe whereby light is redshifted as it travels further from the emitting source. Hubble suspected that perhaps his findings may represent the de Sitter effect, however, Way 2013 notes that, “Thus far historians have unearthed no evidence that Hubble was searching for the clues to an expanding universe when he published his 1929 paper (Hubble 1929b).” Indeed, nearly two decades after the 1929 publication, Hubble 1947 remarks that better data may indicate that, “redshifts may not be due to an expanding universe, and much of the current speculation on the structure of the universe may require re-examination.” It is thus somewhat of a paradox that, in tandem with the other reasons outlined, Hubble is credited with discovering that the Universe is expanding.
The term redshift stems from the fact that when astronomers (e.g., V. Slipher) examined the spectra of certain galaxies, they noticed that although a particular spectral line should have appeared in the blue region of the spectrum (as measured in a laboratory): the line was actually shifted redward. Hubble 1947 explained that, “light-waves from distant nebulae [galaxies] seem to grow longer in proportion to the distance they have travelled It is as though the stations on your radio dial were all shifted toward the longer wavelengths in proportion to the distances of the stations. In the nebular [galaxy] spectra the stations (or lines) are shifted toward the red, and these redshifts vary directly with distance–an approximately linear relation. This interpretation lends itself directly to theories of an expanding universe. The interpretation is not universally accepted, but even the most cautious of us admit that redshifts are evidence either of an expanding universe or of some hitherto unknown principle of nature.”
Top, spectra for galaxies that are redshifted (image credit: JPL/Caltech/Planck).
As noted above, Hubble was not the first to deduce a velocity-distance relation for galaxies, and Way 2013 notes that, “Lundmark (1924b): first distance vs. velocity plot for spiral nebulae [galaxies] …Georges Lemaitre (1927): derived a non–static solution to Einstein’s equations and coupled it to observations to reveal a linear distance vs. redshift relation with a slope of 670 or 575 km/s/Mpc (depending on how the data is grouped) …” Although Hubble was aware of Lundmark’s research, he and numerous other astronomers were likely unaware of the now famous 1927 Lemaitre study, which was published in an obscure journal (see Livio 2012 (Nature), and discussion therein). Steer 2013 notes that, “Lundmark’s [1924] distance estimates were consistent with a Hubble constant of 75 km/s/Mpc [which is close to recent estimates].” (see also the interpretation of Peacock 2013). Certain distances established by Lundmark appear close to present determinations (e.g., M31, see the table above).
So why was Hubble credited with discovering the expanding Universe? Way 2013 suggests that, “Hubble’s success in gaining credit for his … linear distance-velocity relation may be related to his verification of the Island Universe hypothesis –after the latter, his prominence as a major player in astronomy was affirmed. As pointed out by Merton (1968) credit for simultaneous (or nearly so) discoveries is usually given to eminent scientists over lesser-known ones.” Steer told Universe Today that, “Lundmark in his own words did not find a definite relation between redshift and distance, and there is no linear relation overplotted in his redshift-distance graph. Where Lundmark used a single unproven distance indicator (galaxy diameters), cross-checked by a single unproven distance to the Andromeda galaxy, Hubble used multiple indicators including one still in use (brightest stars), cross-checked with distances to multiple galaxies based on Cepheids variables stars.”
Concerning assigning credit for the discovery of the expansion of the Universe, Way 2013 concludes that, “Overall we find that Lemaitre was the first to seek and find a linear relation between distance and velocity in the context of an expanding universe, but that a number of other actors (e.g. Carl Wirtz, Ludwik Silberstein, Knut Lundmark, Edwin Hubble, Willem de Sitter) were looking for a relation that fit into the context of de Sitter’s [Universe] Model B world with its spurious radial velocities [the redshift].” A partial list of the various contributors highlighted by van den Bergh 2011 is provided below.
“The history of the discovery of the expansion of the Universe may be summarized [above],” van den Bergh 2011 (image credit: van den Bergh/JRASC/arXiv).Way and Nussbaumer 2011 assert that, “It is still widely held that in 1929 Edwin Hubble discovered the expanding Universe … that is incorrect. There is little excuse for this, since there exists sufficient well-supported evidence about the circumstances of the discovery.”
In sum, the author’s personal opinion is that Hubble’s contributions to astronomy were seminal. Hubble helped convince astronomers of the extragalactic distance scale and that a relationship existed between the distance to a galaxy and its velocity, thus propelling the field and science forward. His extragalactic distances, albeit flawed, were also used to draw important conclusions (e.g., by Lemaitre 1927). However, it is likewise clear that other individuals are meritorious and deserve significant praise. The contributions of those scientists should be highlighted in parallel to Hubble’s research, and astronomy textbooks should be revised to emphasize those achievements A fuller account should be cited of the admirable achievements made by numerous astronomers working in synergy during the 1920s.
There are a diverse set of opinions on the topics discussed, and the reader should remain skeptical (of the present article and other interpretations), particularly since knowledge of the topic is evolving and more is yet to emerge. Two talks from the “Origins of the Expanding Universe: 1912-1932” conference are posted below (by H. Nussbaumer and M. Way), in addition to a talk by I. Steer from a separate event.
A April Fools Day conjunction of Pluto & Jupiter, the likes of which you'll never see! (Credit: NASA/JPL/USGS(Jupiter) & NASA?ESA & M. Buie of the SWRI (Pluto)
The first day of April is always a traditional time for pranks and puns, and astronomers and scientists aren’t above an April Fools’ Day shenanigan or two. Hey, I gotta admit, as a freelance science journalist, even my radar will be up tomorrow as I’m sure that someone will try to slide some wowzers by the credulous media, as they always have in the past. If the aliens wanted to conquer the Earth it’s wide open to ‘em on April 1st, I’m just sayin’. Who would believe the tweets were for real, as they landed ray guns ablaze on the White House lawn? Trust us; you won’t see such April Fools’ hi-jinks from Universe Today. If you read it here, the alien invasion is for real, and you can begin stockpiling food and ammo appropriately in the best tradition of Falling Skies.
Here are just some of the classic astronomical April Fools’ jokes perpetrated in the past:
In 1974, John Gribbin published The Jupiter Effect, claiming that a Grand Alignment of the planets would spell doomsday for the Earth on March 10th, 1982. On April 1st 1976, Astronomer Sir Patrick Moore made an announcement along a similar vein to BBC listeners. A rare conjunction of the planets Pluto (which was still classified as a planet at the time) & Jupiter would weaken the gravitational field of the Earth at precisely 9:47AM. This would cause the law of gravity to become temporarily suspended, and cause things to fly about. Big hint: Pluto was nowhere near the gas giant at the time. Not that it would matter or have any consequence for the Earth! Although the hoax was quickly revealed, that didn’t stop several listeners from calling in and reporting observed results from the fake Jovian-Plutonian Gravitational effect!
The first star party? Galileo shows off the sky in Saint Mark’s square in Venice. Note the lack of adaptive optics. (Illustration in the Public Domain).
Many questionable astrophysical papers have been spotted in the wild trying to sneak past the guardians-that-be over the years on & around April 1st. On April Fools’ past, we’ve learned that Schrödinger’s Cat is not alone, the supposed discovery of the “bigon” particle, and that the “non-detection of the tooth fairy” has been reported. Hey, never let it be said that science geeks lack a sense of humor. What’s especially amazing is when one of these tall tales actually makes it past the credulous media and into print!
One of our favorites hit the servers last year on March 30th just in time to gain traction for April Fools’ Day with the cryptic title On the influence of the Illuminati in astronomical adaptive optics. OK, I’ll admit we didn’t question the veracity of the claim for oh, like, maybe a tenth of a second. For those without enlightenment into the world of Woo, the Illuminati are purported to be the shadow cult organization going back to the Middle Ages that’s supposed to be behind, well, every nefarious plot in modern society. “They put the eye over the pyramid on the back of a dollar bill, man…” as some true believers will claim. And while they didn’t have adaptive optics technology way back in Galileo’s time, the mock study does assert a tenuous link between the Illuminati and the “astronomical rise” of Brittany Spears and Lady Gaga.
Phobos (above) and Deimos (bottom) close up; no Martian construction projects noted. (Credit: NASA).
Are Martians secretly hollowing out a base on the Moons of Barsoom? The Moons of Mars were also the setting for an April Fools’ prank in 1959. The Martian moons are bizarre in their own right. Orbiting at 6,000 & 20,060 kilometres above the surface of the Red Planet, Phobos & Deimos are almost certainly captured asteroids. In fact, Phobos orbits its primary closer than any other moon in the solar system. Phobos will crash into Mars millions of years in the future.
The hoax was perpetrated when Walter Scott Houston, posing as Dr. Arthur Hayall of the fictitious University of the Sierras made a claim in the Great Plains Observer that Phobos & Deimos were in fact artificial satellites. Though the joke ran its course, the idea has cropped up in fringe circles over the years. Russian scientist Iosif Shklovsky made a similar allusion years later, asserting that the low density of Phobos indicated that was hollow (!) Mariner 9 returned the first close-up views of Phobos in 1971, showing a decidedly asteroid-looking appearance. Of course, this hasn’t stopped the likes of folks like Richard Hoagland (he of the face on Mars) from resurrecting the outlandish claim, all of which started as a practical joke. And of course, with the advent of the Internet, you don’t have to wait until April 1st to receive modern day hoax emails proclaiming “MARS WILL APPEAR AS BIG AS THE FULL MOON!!!” which now apparently happens every August.
A moon for Mercury… (or not!) (Credit: NASA/Johns Hopkins University/APL/Carnegie Institution of Washington).
Spurious moons are apparently the “low-hanging fruit” of astronomical April Fools’ pranks. In 2012, an image of a purported moon of the planet Mercury’s as discovered by the MESSENGER spacecraft appeared in the JPL Photojournal. The captioning declared the moon had been named Caduceus and was 70 metres in diameter. Perhaps such a prank is appealing because there’s nothing immediately outlandish about the idea. New moons get discovered periodically on first reconnaissance missions past planets. For a brief time in 1974, Mariner 10 project scientists did indeed think they had discovered a Mercurial moon. Reading on through the press release, however, revealed that a collision course of MESSENGER with the moon was set to cause it to “arrive at Earth by 2014.” The “moon” also bared a suspicious resemblance to the asteroid 243 Ida as seen by the Jupiter-bound Galileo spacecraft in 1993.
Some April Fools’ hoaxes have presented ideas that have actually gained scientific traction in reality over the years. On March 31st, 2005, NASA’s Astronomy Picture of the Day website contained the teaser “Water on Mars!” for its next presentation to follow on the next day. A flurry of discussion followed; was there a discovery from the Spirit & Opportunity rovers forthcoming? We should’ve checked the calendar first. The next day, APOD featured water… in a glass, sitting atop a Mars bar. What’s ironic is that recent announcements from the Mars Science Laboratory support the idea of ancient water on the Red Planet, so the MSL may well have had the last laugh.
Sulfate-rich sandstone imaged by Opportunity (left) and Curiosity (right). Both hint at ancient surface water on Mars. (Credit: NASA/JPL-Caltech/Cornell/MSSS).
The Museum of Hoaxes also hosts a list of astronomy & space-themed April Fools’ Day pranks that have been perpetrated over the years. From a Soviet space capsule landing outside of Kankakee, Illinois to life discovered on Jupiter in 1996, it’s all enshrined for the curious. One of our faves is Google’s 2004 announcement that they were accepting applications at a new research center… based on the Moon in Copernicus crater. The ability to survive “with limited access to such modern conveniences as soy low-fat lattes,” was cited as a prerequisite, but a sushi chef and two massage therapists would be on site. At least the assignment wouldn’t be totally austere!
Closeup of Copernicus crater region… note the distinct lack of soy lattes! (Photo by author).
What astronomical hi-jinks await us tomorrow as we flip our calendars over to April 1st, 2013? Feel free to tell us here at Universe Today of your true tales of April Fools’ astronomy pranks past & present that you’ve spotted in the wild. Think twice before re-tweeting that link tomorrow, and don’t believe those reports of “nearby gamma-ray bursts of doom” or “alien invasions…” or at least, wait until you’ve seen the “greens of their eyes!”
A time exposure of the Allen Telescope Array. (Credit: Seth Shostak/The SETI Institute used with perimssion).
In 1888, astronomer Simon Newcomb uttered now infamous words, stating that “We are probably nearing the limit of all we can know about astronomy.” This was an age just prior to identifying faint nebulae as separate galaxies, Einstein’s theory of special and general relativity, and an era when a hypothetical substance called the aether was said to permeate the cosmos.
Newcomb would scarcely recognize astronomy today. Modern observatories span the electromagnetic spectrum and are unlocking the secrets of a universe both weird and wonderful. Modern day astronomers rarely peer through an eyepiece, were it even possible to do so with such bizarre instruments. What follows are some of the most unique professional ground-based observatories in operation today that are pushing back our understanding of the universe we inhabit.
VERITAS: Based at the Fred Lawrence Whipple Observatory in southern Arizona, the Very Energetic Radiation Imaging Telescope Array System (VERITAS) is an observatory designed to observe high energy gamma-rays. Its array consists of four 12-metre aperture reflectors each comprised of 350 mirror scintillators. Each VERITAS array has a 3.5° degree field of view and the array has been fully operational since 2007. VERITAS has been used to study active galactic nuclei, gamma-ray bursts, and the Crab Nebula pulsar.
Looking down one of IceCube’s detector bore holes. (Credit: IceCube Collaboration/NSF).
IceCube: Not the rapper, IceCube is a neutrino detector in based at the Amundsen-Scott South Pole Station in Antarctica. IceCube watches for neutrino interactions by use of thousands of photomultipliers suspended up to 2.45 kilometres down into the Antarctic ice sheet. With a total of 86 detector strings completed in 2011, IceCube is currently the world’s largest neutrino observatory and is part of the worldwide Supernova Early Warning System. IceCube will also complement WMAP and Planck data and can actually “see” the shadowing effect of the Moon blocking cosmic ray muons.
Liquid Mirror Telescopes: One of the more bizarre optical designs out there in the world of astronomy, liquid mirror telescopes employ a large rotating dish of mercury to form a parabolic mirror. The design is cost effective but does have the slight drawback of having to aim directly at the zenith while a swath of sky passes over head. NASA employed a 3-metre liquid mirror telescope as part of its Orbital Debris observatory based near Cloudcroft, New Mexico from 1995-2002. The largest one in the world (and the 18th largest optical telescope overall) is the 6-metre Large Zenith Telescope in the University of British Columbia’s Malcolm Knapp Research Forest.
An aerial view of LIGO Hanford. (Credit: Gary White/Mark Coles/California Institute of Technology/LIGO/NSF).
LIGO: Designed to detect incoming gravity waves caused by pulsar-black hole mergers, the Laser Interferometer Gravitational-Wave Observatory (LIGO) is comprised of a pair of facilities with one based in Hanford, Washington and another in Livingston, Louisiana. Each detector is consists of a pair of 2 kilometre Fabry-Pérot arms and measures a laser beam shot through them with ultra-high precision. Two geographically separate interferometers are needed to isolate out terrestrial interference as well as give a direction of an incoming gravity wave on the celestial sphere. To date, no gravity waves have been detected by LIGO, but said detection is expected to open up a whole new field of astronomy.
The VLBA antenna located at St. Croix in the Virgin Islands. (Credit: Image courtesy of the NRAO/AUI/NSF).
The Very Long Baseline Array: A series of 10 radio telescopes with a resolution the size of a continent, the Very Long Baseline Array (VLBA) employs observatories across the continental United States, Saint Croix in the U.S. Virgin Islands, and Mauna Kea, Hawaii. This is effectively the longest radio interferometer in the world with a baseline of over 8,600 kilometres and a resolution of under one milliarcseconds at 4 to 0.7 centimetre wavelengths. The VLBA has been used to study H2O megamasers in Active Galactic Nuclei and measure ultra-precise positions and proper motions of stars and galaxies.
LOFAR: Located just north of the town of Exloo in the Netherlands, The LOw Frequency Radio Array is a phased array 25,000 antennas with an effective collection area of 300,000 square metres. This makes LOFAR one of the largest single connected radio telescopes in existence. LOFAR is also a proof on concept for its eventual successor, the Square Kilometre Array to be built jointly in South Africa, Australia & New Zealand. Key projects involving LOFAR include extragalactic surveys, research into the nature of cosmic rays and studies of space weather.
One of the water tank detectors in Pierre Auger observatory. (Wikimedia Image in the Public Domain).
The Pierre Auger Observatory: A cosmic ray observatory located in Malargüe, Argentina, the Pierre Auger Observatory was completed in 2008. This unique instrument consists of 1600 water tank Cherenkov radiation detectors spaced out over 3,000 square kilometres along with four complimenting fluorescence detectors. Results from Pierre Auger have thus far included discovery of a possible link between some of the highest energy events observed and active galactic nuclei.
The GONG installation at the Cerro Tololo Interamerican observatory in Chile. (Credit: GONG/NSO/AURA/NSF).
GONG: Keeping an eye on the Sun is the goal of the Global Oscillation Network Group, a worldwide network of six solar telescopes. Established from an initial survey of 15 sites in 1991, GONG provides real-time data that compliments space-based efforts to monitor the Sun by the SDO, SHO, and STEREO A & B spacecraft. GONG scientists can even monitor the solar farside by use of helioseismology!
The Allen Telescope Array: Located at Hat Creek 470 kilometres northeast of San Francisco, this array will eventually consist of 350 Gregorian focus radio antennas that will support SETI’s search for extraterrestrial intelligence. 42 antennas were made operational in 2007, and a 2011 budget shortfall put the status of the array in limbo until a preliminary financing goal of $200,000 was met in August 2011.
The YBJ Cosmic Ray Observatory: Located high on the Tibetan plateau, Yangbajing International Cosmic Ray Observatory is a joint Japanese-Chinese effort. Much like Pierre-Auger, the YBJ Cosmic Ray Observatory employs scintillators spread out along with high speed cameras to watch for cosmic ray interactions. YBJ observes the sky in cosmic rays continuously and has captured sources from the Crab nebula pulsar and found a correlation between solar & interplanetary magnetic fields and the Sun’s own “cosmic ray shadow”. The KOSMA 3-metre radio telescope is also being moved from Switzerland to the YBJ observatory in Tibet.
An Operation Moonwatch team in action based out of Terre Haute, Indiana. (Courtesy of Keep Watching the Skies! Author Patrick McCray, used with Permission).
Amateur astronomers have done more than just watch the skies, they’ve been a national security asset. In the mid-1950’s, it was realized that the reality of the Space Age was at best only a decade away. Sub-orbital German V-2 rockets captured by the Soviets and the United States were reaching higher and higher altitudes, and it was only a matter of time before orbital velocity would be achieved.
Keep in mind, this was the age of backyard bomb shelters, “duck and cover” drills, and civil preparedness as Cold War fever reached a heightened pitch. Ground Observer Corps encouraged and trained citizen groups how to spot and report enemy bombers approaching the U.S coast in preparation for a nuclear confrontation. And remember, there was no reason to think that this build up wouldn’t extend to the militarization of space. It was in this era that Operation Moonwatch was born.
Conceived by Harvard astronomer Fred Whipple, Operation Moonwatch was the “Galaxy Zoo” of its day. The idea was simple; teams of observers around the world would track, time and record satellite passes over their location and feed this data back to the computation center at Cambridge, Massachusetts (telephone, Western Union or ham radio were the methods of the day) This data would give engineers information as to where to point their enormous Baker-Nunn cameras. These instruments were wide-field Schmidt cameras that could cover large swaths of the sky. They were to be positioned at 12 locations worldwide to keep tabs on satellites in low Earth orbit (LEO).
A Baker-Nunn satellite tracking camera ready for action. (Credit: NASA).
To be sure, there were obstacles to overcome. The Baker-Nunn cameras were well behind schedule, and the entire system was struggling to come online by mid-1958 in time for the International Geophysical Year (IGY). School and community groups had to be organized, trained, and equipped. Knowing precise location in the pre-GPS era had to be addressed. Many purchased optical kits available from Radio Shack, while many teams built their own. Then there was the dilemma of what a satellite would actually look like to an observer on the ground. Could a trained spotter even see it? Civil Air Patrol groups experimented with various trial substitutions, such as following aircraft, flocks of birds and bats at dusk and even tracking pebbles tossed into the sky!
Operation Moonwatch was also to play a part of the 1958 International Geophysical Year. Many doubted to effectiveness of amateur groups, but public interest ran high. Then on October 4th 1957, the world was caught off guard as Sputnik 1 lifted off from the Baikonur Cosmodrome.
The world was stunned that the Soviets had beaten the West into space. The National Advisory Committee for Aeronautics (later to become NASA in 1958) had yet to achieve a successful orbital launch, and the United States Naval Research Laboratory was still floundering to get the Vanguard program off the pad. The launch of Sputnik found a scant few Moonwatch teams at the ready to catch its first dusk passes over the United States. Keep in mind, the Sputnik satellite was too small and faint to see with the naked eye. What most casual observers in the general public saw (remember the opening scenes in the movie October Sky?) was actually the rocket booster that put Sputnik into space.
Moonwatch teams would “look up by looking down” using a bench mounted telescope that looked at a reflective plate aimed skyward. With observers arranged in a row aimed at a picket line, they would call out when the target satellite crossed the local meridian. This would in turn be documented by an onsite recorder for transmission.
With Sputnik, the Operation Moonwatch volunteers found themselves thrust into the spotlight. Newspapers & radio shows clamored to interview volunteers, as the public suddenly became obsessed with space. Moonwatchers followed and documented to launch of the dog Laika aboard Sputnik 2 on November 3rd, 1957, and when the U.S. finally launched its first satellite Explorer I on February 1st 1958 Operation Moonwatch tracked it. Magazines such as National Geographic and Boys Life ran articles on the project and told teams how they could participate. When Sputnik 4 reentered over the U.S. on September 1962, it was data from Operation Moonwatch observers that proved vital in its recovery.
How Operation Moonwatch fit into the hierarchy. Note how amateur groups were associated with this press. (Credit: NASA archives, The Role of the NAS & TPESP).
Moonwatch was disbanded in 1975, but many volunteers continued tracking satellites and sharing data on their own. I always think that it’s fascinating that three very early satellites from the early days of Operation Moonwatch are still in orbit and can been seen with a good pair of binoculars and a little patience , Vanguards 1, 2 & 3. It could be argued that Operation Moonwatch provided a civilian means to monitor the goings on of governments in low Earth orbit and may have contributed to the Outer Space Treaty outlawing the use of nuclear weapons in space. Another fortunate occurrence of the era was the establishment of a civilian space agency in the U.S., argued for successfully by Dr. James Van Allen. How different would the course of history have been if the U.S. space program had become a “fourth branch” of the military?
Cincinnati plaque commemorating Operation Moonwatch. (Brian Van Flandern Public Domain image).
Today, modern satellite trackers still follow, image and share information on satellites worldwide. This effort transcends borders; when hazardous payloads such as Russia’s failed Mars mission Phobos-Grunt reentered in early 2012 satellite trackers documented its final passage, and efforts are still underway to keep tabs on the USAF’s X-37 spy satellite. One can also see a stark contrast between the efforts to enlist civilian effort during the Cold War and the modern Global War on Terrorism. Interest in science was at an all-time high in the 1950’s, as it was realized the West might be lagging behind in science education. In a post-9/11 era, there almost seems to be a movement to isolate participation. Many model rocketry groups are under increased restriction, and even amateur astronomers may see essential tools such as green laser pointers restricted for use.
Image of Space Shuttle Discovery on STS-119 captured from the ground… note the NASA “Blue Meatball” logo on the wing! (Credit: Ralf Vandebergh, used with permission).
But the good news is, anyone can still track a satellite from the comfort of their own backyard all in the spirit of Operation Moonwatch. DARPA announced a project last year which may resurrect a program similar to Operation Moonwatch. Named SpaceView, this program seeks to augment the U.S. Air Force’s Space Surveillance Network. Keep an eye on the sky, and remember a dedicated few amateur observers that played a crucial role in modern history as you watch satellites drift silently by in the twilight skies.
For more on the fscinating hostory of Operation Moonwatch, read Patrick McCray’s Keep Watching the Skies!
The crew of Apollo 9: Commander James McDivitt, Command Module Pilot Dave Scott and Lunar Module Pilot Rusty Schweickart. Credit: NASA
“On the success of Apollo 9 mission hangs the hope for future manned missions to the Moon,” said famous CBS newsman Walter Cronkite. HD TV it’s not, but this is a fun look back at actual news footage from the Apollo 9 mission, which landed back on Earth on March 13, 1969, forty-four years ago today.
The ten-day Apollo 9 mission was the first manned flight of the lunar module and while in Earth orbit the crew tested the spacecraft for lunar operations. The crew included Commander Jim McDivitt, Command Module pilot Dave Scott and one of our favorite astronauts, the Lunar Module pilot Rusty Schweickart.
They successfully demonstrated the complete rendezvous and docking operations and conducted an EVA during their 151 Earth orbits. The mission carried the largest payload at that point in time to Earth orbit.
Io and Jupiter as seen by New Horizons during its 2008 flyby. (Credit: NASA/Johns Hopkins University APL/SWRI).
Sometimes the tried and true methods are still the best, even in observational astronomy. Researchers at the University of Prague demonstrated this recently in a study of the eclipsing binary system V994 Herculis (V994 Her).
Researchers P. Zasche and R. Uhla used a method known as the Light-travel-time Effect to verify that V994 Her is actually a double binary. If that method sounds familiar to any astronomy historians out there, that’s because it was first used by 17th century astronomers to gauge the speed of light.
V994 Her is a rarity in the skies. While many eclipsing binaries are known, V994 Her is one of only six quadruple eclipsing binary stars discovered. An eclipsing binary star is a system where the two stars pass one in front of the other from our line of sight. Although too close to be split visually, eclipsing binaries rise and fall in brightness periodically. One famous example is the star Algol (Beta Persei) in the constellation Perseus. Algol means the “Demon Star” in Arabic, which suggests that its curious nature was known to Arab astronomers in pre-telescopic times.
Mercury and Mars on February 8, 2013. See how close they'll be? Image credit: Stellarium.
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The history of astronomy is littered with astronomical objects in the solar system that have fallen to the wayside. These include fleeting sightings of Venusian moons, inter-mercurial planets, and even secondary moons of the Earth.
While none of these observations ever amounted to true discoveries, this weekend gives observers and astrophotographers a unique chance to “mimic” a spurious discovery that has dotted astronomical lore: a visual “pseudo-moon” for the planet Mercury. This “moon illusion” will occur on February 8, 2013 during the closest conjunction of two naked eye planets in 2013. February offers a chance to see the fleeting Mercury in the sky, and this conjunction with Mars will provide the opportunity to see how Mercury would look in the night sky if it had a moon!
Mercury has been suspected of having moons before. On March 29th 1974, the Mariner 10 spacecraft became the first mission to image the innermost world up close. Mariner 10 mapped 40-45% of Mercury on 3 successive passes, revealing a pock-marked world not that different than our own Moon. But Mariner 10 also detected something more: brief anomalies in the ultra-violet spectrum suggestive of a moon with a 3 day period. For a very brief time, Mercury was thought to have a moon of its own, and NASA nearly made a press release to this effect. The spectroscopic binary 31 Crateris is now suspect in the anomalous readings. Still, the Mariner 10 observation made researchers realize the observations in the extreme UV were possible over interstellar distances.
The planet Mercury as seen by NASA's MESSENGER spacecraft (Credit: NASA/JHUAPL).
Today, NASA has a permanent emissary orbiting Mercury with its MESSENGER spacecraft. MESSENGER first entered orbit around Mercury on March 18th, 2011 after a series of trajectory changing flybys. MESSENGER has filled in the map of the remainder of Mercury’s surface, with no signs of the anomalous “moon.” Interestingly, MESSENGER was also on the lookout for “Vulcanoids” (tiny asteroids interior to Mercury’s orbit; sorry, Mr. Spock) while enroute to its final orbital insertion. NASA even released an April Fool’s Day prank of a fake “discovery” of a Mercurial moon dubbed Caduceus in 2012.
But MESSENGER has made some fascinating true to life discoveries, such as sampling Mercury’s tenuous exosphere & the possibility of ice at its permanently shadowed poles. Lots of new features have been mapped and named on Mercury, following the convention of naming features after famous deceased artists, musicians and authors set forth by the International Astronomical Union. It’s amazing to think that we had no detailed views at the entire surface of Mercury until the 1970’s, although some ground-based professional observatories and even skilled amateurs are now doing just that.
Fast forward to this weekend. Mercury is just beginning its first apparition of six in 2013 this week and is currently visible low in the dusk sky after sunset to the west. Mercury reaches greatest eastern elongation on February 16th at 18.1° from the Sun. Interestingly, that’s very close to the shortest elongation that can occur. Mercury’s orbit is eccentric enough that greatest elongation as seen from the Earth can vary from 17.9° to 27.8°. This month’s elongation happens within only 5 hours of Mercury reaching perihelion at 46 million kilometers from the Sun. This means that Mercury won’t peak above the dusk horizon for mid-northern latitude observers quite as high as it will during the next evening apparition of the planet in June.
caption =”Looking west 30 minutes after sunset on Feb. 8th from latitude 30° north.
This appearance of Mercury does, however, have some things going for it. First off, the ecliptic sits at a favorable viewing angle, roughly perpendicular to the western horizon at dusk for mid- to high northern latitude observers. This gives Mercury a bit of a “boost” out of the weeds. Secondly, Mercury is a full magnitude (2.512 times) brighter when it reaches maximum elongation near perihelion than aphelion, such as its next appearance in the dawn sky on March 31st of this year. Mercury will reach magnitude -0.5, versus +0.5 in late March.
To see Mercury, find a site with a western horizon free of ground clutter and start sweeping the horizon with binoculars about 15 minutes after local sunset. See a reddish dot just above Mercury? That’s the planet Mars, shining about 7 times fainter than -1.0 magnitude Mercury at magnitude +1.2. Mercury is fast approaching a conjunction with Mars; the two will be only 15’ apart (half the average width of a Full Moon) on the evening of February 8th at 17:00 Universal Time!
If you ever wondered how Mercury would appear with a moon, now is a good time to take a look! Again, binoculars are the best optical tool for the job. Can you see both with the naked eye? Can you place both in the same low power field of view with a telescope? You’ll only have a 15-30 minute window (depending on latitude) to snare the pairing before they follow the setting Sun below the horizon. Photographing the pair will be tricky, though not impossible, as they present a very low contrast against the bright background twilight sky.
caption =”Mercury (lower center) & Mars (upper center) imaged by Mike Weasner on February 5th.
Don’t expect to see detail on Mercury or Mars telescopically; Mercury only appears 5.8” across on the 8th, while Mars is 4” in apparent size. Mars disappears from view later this month to reach solar conjunction on April 18th 2013. The waxing crescent Moon just 1 day after New joins the pair on the evenings of February 10th and 11th.
Now for the “Wow” factor of what you’re seeing. The conjunction of Mars and Mercury only appears close; in reality, they are over 180 million kilometers apart. Mercury is 1.15 Astronomical Units (A.U.s)/178 million kilometers from us on February 8th, while Mars is nearly at its farthest from us at 2.31 A.U.s/358 million kilometers distant. It’s splendid to think that with Curiosity and friends operating on Mars and Messenger orbiting Mercury, we now have permanent robotic “eyes” on and around both!
Credits: Simulation created by the author using Starry Night.
Mercury & Mars courtesy of Mike Weasner and the Cassiopeia Observatory. Used with permission.
Astronomers, both professional and amateur, throughout the world, were saddened yesterday to hear of the death of Sir Patrick Moore. He was the reason many of them became interested in the stars in the first place. For 55 years, from 26 April 1957 until his final broadcast on 3 December 2012, he was our monthly guide to the stars, earning him a place in the Guinness Book of Records as the world’s longest-serving TV presenter of the longest-running programme with the same presenter in television history, The Sky at Night.
He was born Patrick Alfred Caldwell-Moore, at Pinner, Middlesex on 4 Mar 1923 and later moved to Sussex. Heart problems during his youth lead to him being educated at home. When he was 6 he was given a copy of The Story of the Solar System by GF Chambers which began his life long passion for astronomy and 5 years later, at age 11, he joined the British Astronomical Association. By age 14 he was asked to run a small local observatory in East Grinstead.
At the age of sixteen he lied about his age in order to join the Royal Air Force and from 1940 until 1945 he served as a navigator in RAF Bomber Command, reaching the rank of flight lieutenant. It was during the war that his fiancée, a nurse called Lorna, was killed by a bomb in London. He never married, saying later: “there was no one else for me … second best is no good for me … I would have liked a wife and family, but it was not to be.” He was elected a Fellow of the Royal Astronomical Society in 1945.
After the war he began teaching and built his own 12½ inch reflector telescope in his garden and began to observe the moon. In 1952 wrote his Guide to the Moon, the first of over 100 books he was to write in his lifetime, all typed on his 1908 Woodstock typewriter. His detailed maps of the moon’s surface were eventually used by Nasa as part of the preparations for the moon landing.
On 26 April 1957, at 10:30 pm, he presented the first episode of The Sky at Night, which was scheduled to run for only three months. During his 55 years as presenter he only missed a single episode and from 2004 the programme was broadcast from his home as arthritis meant he was unable to travel to the studios any longer.
He was Director of the newly constructed Armagh Planetarium in Northern Ireland from 1959 until 1968 when he returned to England to live at Farthings in Selsey. He covered all the Apollo missions for television reported on the Voyager and Pioneer programmes and in 1966 was the only amateur astronomer to be elected a member of the International Astronomical Union. The Caldwell catalogue of astronomical objects was compiled by him and asteroid 2602 Moore was named in his honour.
He was keen pianist and accomplished xylophone player and composer, a chess player, golfer and cricketer. He travelled extensively to all seven continents, including Antarctica and claimed that he was the only person to have met the first man to fly, Orville Wright, the first man in space, Yuri Gagarin, and the first man on the moon, Neil Armstrong. In 2001, he was knighted for “services to the popularisation of science and to broadcasting” and became the only amateur astronomer ever to be appointed an Honorary Fellow of the Royal Society.
In an interview in 2008, he said: “In astronomy, amateurs have always played a major part, and they still do. Amateurs do things professional astronomers don’t want to do, haven’t time to do or can’t do. And the average amateur knows the sky a great deal better than the average professional. So, amateurs discover comets, novae and so on.”
He never had any formal training himself and was keen to support and promote the real contribution that amateur astronomers can make to science. He made a point of responding to all letters delivered to his house and delighted in helping to encourage anyone who showed an interest in the stars. He famously had no time for conspiracy theorists, UFOlogists or astrologers. He gave lectures, tours and public appearances, seemingly to anybody who asked. though he held many views that I will kindly call ‘old fashioned’ and move on, he was happy for people to visit his observatory at his beloved home in FSelsey, which became effectively an open house and science centre. When the news of his death broke tributes poured in from friends and colleagues across the UK and around the world, many feeling they had lost, not just the man responsible for sparking their interest in astronomy, but a mentor and friend, many had stories of his generosity to share.
British amateur astronomer Sir Patrick Moore (center), with co-presenter Chris Lintott (left), and the astrophysicist guitarist Brian May (right). Credit: Steve Elliot.
Chris Lintott, Sir Patrick’s co-presenter on the Sky at Night said “Sir Patrick dedicated his life to talking about astronomy at any opportunity – not out of a desire to make a name for himself or to further an agenda, but because he thought the world would be a better place if he did so.”
Linitott told Universe Today that even though Moore was based in the UK, his appeal was international.
“I remember being at the IAU and finding that astronomers from all over the world were queuing up to thank him for sparking their interest,” Lintott said via email. “He also brought amateurs and professionals together, treating everyone as an equal.”
In a statement, musician, astrophysicist and another “Sky at Night” co-presenter Brian May said called Moore a “dear friend and a kind of father figure to me.” adding, “Patrick will be mourned by the many to whom he was a caring uncle, and by all who loved the delightful wit and clarity of his writings, or enjoyed his fearlessly eccentric persona in public life. Patrick is irreplaceable. There will never be another Patrick Moore. But we were lucky enough to get one.”
Another presenter, Paul Abel, gave an interview about Sir Patrick this morning, and you can hear the audio here.
The theme tune for Sky at Night is the first movement from Pelléas et Mélisande,’ At the Castle Gate’ by Sibelius. When I heard of his death I posted the video in tribute to him and many commented that after the first few bars they expected to hear Sir Patrick’s distinctive voice wishing them a ‘Good evening’, I think that is true of a generation of astronomers. Thank you Sir Patrick.
Sir Patrick Moore, one of the world's greatest astronomy popularizers. He wrote more than 70 books and was the host of the long-running BBC TV series "The Sky at Night".
Astronomer, author and television personality Sir Patrick Moore has died. He was 89. A statement from friends and staff from the long-running BBC television show “The Sky at Night,” said Moore “passed away peacefully” at his home in in the UK. He had been hospitalized last week and after “it was determined that no further treatment would benefit him, and it was his wish to spend his last days in his own home, Farthings, where he today passed on, in the company of close friends and carers and his cat Ptolemy.”
Moore presented “The Sky At Night” for over 50 years, making him the longest-running host of the same television show ever. He also wrote dozens of books on astronomy.
Moore was said to be “an inspiration to generations of astronomers,” and was on “The Sky at Night” right up until the most recent episode.
“His executors and close friends plan to fulfil his wishes for a quiet ceremony of interment, but a farewell event is planned for what would have been Patrick’s 90th birthday in March 2013.”
Chris Lintott, co-presenter and co-author with Moore, told Universe Today that even though Moore was based in the UK, his appeal was international.
“I remember being at the IAU and finding that astronomers from all over the world were queuing up to thank him for sparking their interest,” Lintott said via email. “He also brought amateurs and professionals together, treating everyone as an equal.”
!["The history of the discovery of the expansion of the Universe may be summarized [above]", S. van den Bergh 2011. Image credit: S. van den Bergh/JRASC/arXiv.](https://www.universetoday.com/wp-content/uploads/2013/04/history.jpg)
