The first meeting of the Upper Atmosphere Research Panel, known more informally as the V2 Panel, is held, comprised of researchers from various universities, industry, and the military, to decide on peaceful uses for the nearly 80 rockets’ worth of German V2 rocket hardware seized in Germany at the end of World War II. The technology of the rockets themselves will be studied, while payloads are proposed to study the properties of Earth’s upper atmosphere, radiation received from the sun, and the environment of space itself. Also of key importance will be reverse-engineering the V2 to aid in the design of American-made sounding rockets. Eventually the German scientists and engineers who were taken into custody with the captured hardware will be brought to the U.S. to continue their research.
Using a telescope at Mount Wilson Observatory, astronomer Seth Nicholson discovers Ananke, a tiny moon of Jupiter orbiting the huge planet at an average distance of 21 million miles and at a high inclination relative to Jupiter’s equator. Ananke is most likely a captured asteroid or the remnant of a captured asteroid, and other small Jovian moons in the same orbit may be other pieces of the captured (and shredded) body. Ananke is the first Jovian moon discovered in nearly two decades, and it will be over two more decades before another is found.
After months of lobbying the U.S. Air Force and the Advanced Research Projects Agency (ARPA) for help in funding a large-aperture radar/radio telescope dish for studies of Earth’s ionosphere and the space that lies beyond, Cornell University’s Bill Gordon publishes a report in the journal of the School of Electrical Engineering. Gordon’s report, setting out the basic parameters for the project, includes a reflector dish diameter of one thousand feet – a daunting prospect from a structural engineering perspective. Sites in Texas and upstate New York are considered before a natural limestone “bowl” south of the city of Arecibo, Puerto Rico emerges as a promising candidate site.
Proposed and designed by Cornell University, and funded by the Adavanced Research Projects Agency (ARPA), the Arecibo Ionospheric Research Center – a thousand-foot radar and radio telescope dish – begins construction in a natural limestone bowl south of Barrio Esparanza, Arecibo, Puerto Rico. Construction will take over three years, at a cost of nearly $10,000,000, with a steel feed receiver structure supported in mid-air over the parabolic dish by some five miles of steel cables. Facilities are constructed for scientists visiting the eventual facility, and additional facilities are constructed to shape aluminum into the mesh structure of the telescope dish on-site, a more economical approach than having those parts of the telescope shipped in from outside. Though conceived and pitched as a means of studying the ionosphere, with possible defense applications such as missile detection, the Arecibo facility will makes its best known contributions to astronomy after it opens.
The United States Federal Communications Commission places a ten-year hold on television station licenses for UHF channel 37. Channel 37’s bandwidth, in the 608-614 megahertz range, is vital to the burgeoning science of radio astronomy. The FCC immediately sets about reallocating channels on the UHF dial for 18 television stations across America, which had previously been allocated channel 37 on their licenses. One month later, the ban on broadcasting in that part of the spectrum is made global; no television station in the United States, Mexico, Canada, and several other countries will ever occupy those frequencies. When the ban comes up for review again in 
Nestled into a mountainous forest region of Puerto Rico, the Cornell University-funded Arecibo Radio Telescope officially begins operations. With a diameter of a thousand feet, this remains the world’s largest radio telescope until the 21st century. Studies of Earth’s ionosphere are high on the priority list, but radio astronomy isn’t far behind, and important discoveries are made at Arecibo within months of it opening.
Using a 20-foot, horn-shaped receiver built at Bell Laboratories’ Holmdell, New Jersey facility for tests of the Echo-1 satellite in 
NASA launches its first space-based telescope, the unmanned Orbiting Astronomical Observatory satellite, into Earth orbit. Weighing nearly two tons and sporting visible, ultraviolet, X-ray and gamma ray astronomy capabilities, OAO is in trouble mere minutes after it goes into service: a serious electrical failure leaves the spacecraft in a blind tumble, and it will be declared a loss three days after launch. NASA will attempt another OAO launch in 1968.
French astronomer Audouin Dollfus discovers Janus, the tenth discovered natural satellite of the planet Saturn, orbiting just beyond the outer edge of Saturn’s ring. Confusion is caused when, mere days later, an American astronomer discovers another body in a near-identical orbit that cannot be reconciled with the orbit calculated for Janus. Only in the late 1970s will a theory emerge that explains the inconsistencies as the presence of two moons moving around Saturn as a co-orbital pair, occasionally swapping positions. Janus’ existence will be verified in 1980 by Voyager 1. (Janus is shown here in a 21st century Cassini photo.)
Just days after the discovery of a satellite in a near-identical orbit, U.S. Naval Observatory astronomer Richard Walker discovers Epimetheus, another natural satellite of the planet Saturn, again orbiting just beyond the outer edge of Saturn’s ring. Many of Walker’s fellow astronomers believe this is merely a second sighting of Janus, discovered mere days before, but irregularities in the computed orbits vex astronomers well into the 1970s, at which point it is conceded that the observations are best explained by two satellites in a very close orbit to one another. Epimetheus and Janus will next be spotted by Voyager 1 in 1980, conclusively proving the existence of two bodies. Epimetheus’ name won’t be made official until 1983. (Epimetheus is shown here in a 21st century Cassini photo.)
Cornell University student Richard Lovelace, working at the Cornell-funded Arecibo Radio Telescope in Puerto Rico, uses the massive telescope and its on-site computers to determine the rotational period of a pulsar discovered near the center of the Crab Nebula, approximately 6,500 light years from Earth. The position of the pulsar relative to the nebula strengthens the case for pulsars and (still hypothetical) neutron stars occurring at the heart of supernova remnants. The Crab Nebula pulsar had been discovered only three years earlier.
In the broad daylight of mid-afternoon, an asteroid measuring somewhere between 10 and 50 feet in diameter plows through Earth’s atmosphere over North America, creating a long-tailed fireball across the sky. Undetected before its close pass – only 35 miles from Earth’s surface – asteroid US19720810 skips off of the atmosphere and back into space, having lost half of its mass to the frictional heating of plummeting through the atmosphere. The spectacle lasts only a couple of minutes, and US19720810 will make another pass by the Earth in 
NASA launches the third and final Orbiting Astronomical Observatory satellite, given the nickname “Copernicus” when it successfully enters service near the 500th anniversary of the birth of the famed astronomer of the same name. OAO-3 is a joint venture between NASA and universities in the U.S. and the U.K., again focusing largely on ultraviolet observation of the sky, and it is instrumental in the discovery and study of long-period pulsars. OAO-3 will remain in service through February 1981, its successful nine-year mission lending weight to the ongoing construction and planning of NASA’s Space Telescope project, later to be known as the Hubble Space Telescope.
NASA launches Explorer 48, renamed Small Astronomy Satellite B, from an Italian-owned offshore launch platform off the coast of Kenya. SAS-B is a smaller spacecraft than NASA’s larger Orbiting Astronomical Observatory (OAO) series, but can be aimed very precisely at any gamma ray sources that it detects. One of those sources turns out to be the pulsar remnant of a massive supernova, a discovery later named Geminga. An electrical fault will end SAS-B’s functionality in 
Astronomer Charles Kowal discovers Leda, a tiny, previously undiscovered moon of Jupiter, using Mount Palomar Observatory’s telescope. With a radius of less than seven miles and an inclined orbit, Leda is the first Jovian moon discovered in over two decades, and is among the last to be discovered using ground-based telescopes in the 20th century.
The first transmission from Earth designed to be a message for interstellar listeners is broadcast from the newly-refurbished Arecibo Radio Telescope in Puerto Rico. Weighing in at 210 bytes, the message is a binary transmission that, when properly assembled, provides a graphical representation of Earth’s solar system, a human being, the makeup of human DNA and the elements from which it is constructed, and the population of Earth. Though the Arecibo dish is pointed in the direction of the M13 globular cluster at the time of the message’s transmission, that cluster will have moved in the 25,000 years it takes for the message to reach that location (and, in any case, Earth and its entire solar system will have moved in the 25,000 additional years it would take to receive a reply), so the message is more of an interstellar technology demo than a message in a bottle.
Astronomers catch fleeting glimpses of a new natural satellite of Jupiter, Themisto, though the initial estimates of its orbit are “off” enough that Themisto becomes “lost” and isn’t observed again until 2000. With a diameter of roughly five miles, Themisto marks the dividing line between the larger inner moons of Jupiter and the widely-scattered menagerie of asteroid-like outer moons orbiting the planet. Astronomers Elizabeth Roemer and Charles Kowal (who discovered another new Jovian moon in 1974) share credit for discovering the moon. Themisto is the last Jovian satellite to be discovered by ground-based telescope in the 20th century.
A team of MIT astronomers, flying in a plane modified to serve as an airborne high-altitude telescope, plans to observe the planet Uranus as it eclipses, or “occults”, a star. But the team observes more occultations than expected both before and after the planet itself passes in front of the star. The inevitable conclusion is that Uranus has rings, made of material too dark to be detected by existing Earthbound telescopes. Further observations are given top priority: NASA’s Voyager 2 space probe, due to lift off later in 1977, may last long enough to reach Uranus, and the newly discovered rings must be taken into account when planning its flyby trajectory.
NASA launches the first High Energy Astronomy Observatory satellite in Earth orbit, continuing the survey of the sky with sensitive detectors designed to find gamma ray and X-ray sources. HEAO-1 will remain in service through January 1979, and will re-enter Earth’s atmosphere in March 1979.
Radio astronomers at Ohio State University observe a signal from the direction of the constellation Sagittarius that seems to jump out from the usual cosmic background noise. The 72-second signal is quickly dubbed the “Wow Signal” (thanks to a hastily scribbled note), and is considered by some to be a strong candidate for a message from an extraterrestrial civilization since its frequency falls almost exactly on the hydrogen line of the electromagnetic spectrum, a wavelength closely watched by the SETI program. But more powerful telescopes listening in on the same region of space in the years and decades to come pick up no further signals. Scientists involved in the initial analysis later admit that the “message” may be of Earthly origin, reflected back from an object in space.
Astronomer James Christy, conducting observations of Pluto at the United States Naval Observatory, discovers a bulging shape present in some photos he’s taken of Pluto, but absent in others. Though the find meets with some skepticism, he has discovered the largest moon of Pluto, Charon, which has a mass of over 50% that of its parent body. Orbiting at only 11,000 miles from Pluto’s surface, Charon has a radius of 750 miles. Within 20 years, closer telescopic examination (including observations using the Hubble Space Telescope) confirm that Charon is separate from Pluto. Since the two bodies are relatively similar in mass, one doesn’t actually orbit the other; rather, they both orbit a center of mass – a barycenter – that lies close to, but not within, Pluto. Further observations in the 21st century lead to the unexpected discovery of four further satellites of Pluto.
NASA launches the second High Energy Astronomy Observatory satellite, which is given the nickname “Einstein” when it enters service. HEAO-2 is a dedicated X-ray telescope with unprecedented sensitivity and accuracy, and will remain in service through March 1982, re-entering Earth’s atmosphere a week afterward.
Tiny Adrastea, a small, asteroid-like moon of Jupiter, is discovered in photos returned by Voyager 2 during its flyby of the planet. Adrastea orbits along the outer edge of Jupiter’s ring system, and is likely to be the body from which material for that ring is ejected. Its close orbit carries it around the planet at a speed faster than Jupiter’s rotation, one of the few bodies in the solar system locked into such a fast orbit.
NASA launches the third and final High Energy Astronomy Observatory satellite into Earth orbit, where it begins studying gamma ray sources and the nature of cosmic rays. There is also an experiment package designed to detect heavy atomic nuclei. HEAO-3 will remain in service through May 1981, and it will re-enter Earth’s atmosphere in December of that year.
NASA launches the unmanned Solar Maximum Mission satellite atop a Delta 3910 rocket, to study cyclical solar flare activity from Earth orbit. Built by Fairchild and relying on a magnetic reaction wheel system to maintain precise aim at the sun, “Solar Max” suffers malfunctions in orbit, and will be able to carry out only limited observations by November 1980. In 1984, Solar Max will become the first satellite to be 
In the journal Science, in an article titled “Extraterrestrial Cause for the Cretaceous-Tertiary Extinction”, Nobel-Prize-winning physicist Luis Alvarez and his son, geologist Walter Alvarez, propose their theory that the 110-mile-wide Chicxulub Crater discovered in the past few decades on the northern tip of the Yucatan Peninsula in Mexico is evidence of a large asteroid collision with Earth, resulting in the widespread death of the dinosaurs 65 million years before the modern day. A contentious peer review of the published theory follows, with many opposing theories proposed, though the Chicxulub hypothesis is eventually accepted as the “smoking gun” that killed the dinosaurs (the theory of an asteroid collision with Earth causing the extinction had been in circulation since the 1950s; the Alvarez theory is the first to point to a specific geological feature as evidence).
Carl Sagan’s groundbreaking science documentary series 