It passed around 60 times the distance of the moon and we heard about it after the fact. And, it was moving really fast. I assume this one would have ended life on Earth had it hit. And, we wouldn't have even known about it. Man, if our orbit around the Sun was a bit earlier when this object came flying by, then this would have been a collision. I would classify it as a near-miss.
60 times is like saying you were 60 feet away from a hole in one. It was moving the same path as the earth revolves around the sun. I doubt it would have ended life on Earth especially if it hit our ocean water.... Casualties yes end of life no.
If it's big enough and travelling fast enough and depending on some other stuff I'm sure: it doesn't matter if it hits land, water, or explodes in the atmosphere. We're ****ed.
Plugging in the numbers 400 meters and 44 km/s into this online calculator for estimating impact effects (http://impact.ese.ic.ac.uk/ImpactEffects/), it seems like it wouldn't have had major global consequences; the thermal effects are localized and the ejecta doesn't seem too bad, with a mean thickness of only 32 microns at a distance of 1000km. But we would have a nice, new 10km crater somewhere on Earth. Of course, those are just the immediate effects. Who knows what that would do to the global economy.
My writer brain has already invented an explanation of this phenomenon. Yes, of course it includes intelligent life. Pssshaaaaa....
It might have been the Superman baby in that hollow crystal ball thing. He got close and was like..."this planet is whack" and decided to go somewhere else. He and the onboard crystal computer probably caught feeds of President Trump talking on Twitter and television on the way in. Yea...it made for a short film.
What's disturbing about this kind of interstellar object is that they can come from any direction and at extreme speeds. We might have very little warning. Asteroids and comets within the Solar System can largely be tracked down and their orbits determined. Our people can do that, given the will and the money necessary to do so. If discovered early enough, it's feasible that we (the planet working together) could mount an expedition, manned and/or robotic, and do something to avoid catastrophe. If we map out our neighborhood, spend the money on current technology, technology that's capable now of accomplishing most of what would be needed to deal with the large objects out there that have our name painted on their nose (and they are out there - it's inevitable), while developing new technologies (need more of that money, lots of it, both for education and for research), then given another decade or so, we might be able to relax a little. But these things? Damn. We better get busy. There's no time to waste.
Update on ‘Oumuamua, Our First Interstellar Object The arrival of an object from beyond the solar system caught astronomers by surprise — but that doesn't mean that they were unprepared to study it. When the first-known object from interstellar space slipped through the inner solar system last month, the welcoming party wasn't quite ready. It passed within 0.25 astronomical unit (37,600,000 km) of the Sun on September 9th — yet wasn't discovered until October 25th. But in the weeks since, astronomers have more than made up for their celestial slight, marshaling telescopes around the world to learn as much as possible about this interloper before it slips out of visual range, never to be seen again. The flurry of activity hasn't been limited to making observations, as officials at the International Astronomical Union struggled with what to call this body. At first astronomers thought it was a comet, based on its extreme orbit, and so the IAU's Minor Planet Center applied the designation C/2017 U1. But when even the deepest telescopic images revealed no hint of a coma or tail, they decided it must be asteroidal, so the designation morphed to A/2017 U1. Behind the scenes, in an unusual effort to name the new object quickly, emails zipped back and forth among the IAU's General Secretary, its Division F president, co-chairs of the IAU's Working Group on Small Body Nomenclature, and the Minor Planet Center. The chosen name, submitted by the team at the Pan-STARRS telescope who discovered it and announced November 6th, is 'Oumuamua. It's a Hawaiian construct combining 'ou (to reach out) and mua(meaning first or in advance of). The second mua is for emphasis. But asteroids are not catalogued by name alone, and this is the first of an entirely new class of object. So, at the suggestion of MPC associate director Gareth Williams, the IAU adopted the identifier "I", for interstellar. "All parties involved in the discussion agreed that the proposal was suitable," he says. "Took less than a day to sort out, announcement followed the day after." As noted in the announcement on MPEC 2017-V17, "Correct forms for referring to this object are therefore: 1I; 1I/2017 U1; 1I/'Oumuamua; and 1I/2017 U1 ('Oumuamua)." Those who work the comet and asteroid trade aren't enamored with the use of "I" — after all, the IAU has gone out of its way to avoid using "I" and "O" in designations because they look too much like the numerals "1" and "0". Several have suggested substituting "E" (for extrasolar) instead, but Williams defends the IAU's decision, noting that "E" could be interpreted as "extraterrestrial," with the implication of intelligence behind the object, and "G" (for "galactic") is too limiting. A Moving Target The first characteristic that marks 'Oumuamua as being from outside our solar system is its orbital eccentricity, 1.19. If you ever took geometry, you might recall that the eccentricity of an ellipse can't exceed 1.0. In fact, dynamicist Bill Gray (Project Pluto) regrets that he didn't pick up on 1I's interstellar nature a few days sooner — his orbit-calculation software kept rejecting the eventual solution as being impossible. The object had already dimmed to 20th magnitude by the time the Pan-STARRS 1 telescope swept it up, so observers worldwide had to scramble to get major facilities to gather more observations before the one-of-a-kind interloper becomes impossibly faint. One lucky break came immediately after the MPC's initial announcement. Observer Joe Masiero (Jet Propulsion Laboratory) just happened be in the middle of a run with the 5-m Hale Telescope at Palomar Observatory, and he quickly obtained a spectrum that's reproduced below and explained in more detail here. There's no obvious absorption that would signify the presence of particular compounds or minerals. But the gentle slope, increasing toward the red (right) end, suggests that 'Oumuamua is not a particularly good match to objects in the Kuiper Belt (which tend to be much redder). Instead, it's the kind of spectrum that a rocky surface would exhibit after being "weathered" by long-term exposure to space radiation. Others have attempted to record the object's light curve and determine its rotation period. Observations by Matthew Knight (University of Maryland) and others show clear variations in the apparent brightness of about 1.2 magnitudes. Knight and his team suspect the object is highly elongated, at least three times longer than it is wide, and rotates with a period of between 3 and 5 hours. The Hubble Space Telescope might have the final word on the character of 1I/2017 U1. A team led by Karen Meech (University of Hawai'i) has been granted HST time to study the quickly disappearing interloper. "Our observations have not executed yet," Meech says, "and the experiment requires three visits — the last of which will be at the end of the year." And, of course, there's been a flurry of speculation about where 'Oumuamua came from. Dynamicist Eric Mamajek (Jet Propulsion Laboratory) points out that the object's incoming velocity (26 km per second) is within 5 km/s of the mean galactic velocity of stars that lie within 25 parsecs (80 light-years) of the Sun, but it does not match the relative velocity of any of the dozen nearest systems. These characteristics all suggest that 'Oumuamua has been drifting among the stars for a very long time, perhaps billions of years. http://www.skyandtelescope.com/astronomy-news/update-on-interstellar-object-oumuamua/
Alien Probe or Galactic Driftwood? SETI Tunes In to 'Oumuamua' Ever since its discovery in mid-October as it passed by Earth already outbound from our solar system, the mysterious object dubbed ‘Oumuamua (Hawaiian for “first messenger”) has left scientists utterly perplexed. Zooming down almost perpendicularly inside Mercury’s orbit at tens of thousands of kilometers per hour—too fast for our star’s gravity to catch—‘Oumuamua appeared to have been dropped in on our solar system from some great interstellar height, picking up even more speed on a slingshot-like loop around the sun before soaring away for parts unknown. It is now already halfway to Jupiter, too far for a rendezvous mission and rapidly fading from the view of Earth’s most powerful telescopes. Astronomers scrambling to glimpse the fading object have revealed additional oddities. ‘Oumuamua was never seen to sprout a comet-like tail after getting close to the sun, hinting it is not a relatively fresh bit of icy flotsam from the outskirts of a nearby star system. This plus its deep red coloration—which mirrors that of some cosmic-ray-bombarded objects in our solar system—suggested that ‘Oumuamua could be an asteroid from another star. Yet those same observations also indicate ‘Oumuamua might be shaped rather like a needle, up to 800 meters long and only 80 wide, spinning every seven hours and 20 minutes. That would mean it is like no asteroid ever seen before, instead resembling the collision-minimizing form favored in many designs for notional interstellar probes. What’s more, it is twirling at a rate that could tear a loosely-bound rubble pile apart. Whatever ‘Oumuamua is, it appears to be quite solid—likely composed of rock, or even metal—seemingly tailor-made to weather long journeys between stars. So far there are few if any wholly satisfactory explanations as to how such an extremely elongated solid object could naturally form, let alone endure the forces of a natural high-speed ejection from a star system—a process thought to involve a wrenching encounter with a giant planet. These bizarre characteristics have raised eyebrows among professional practitioners of SETI, the search for extraterrestrial intelligence, who use large radio telescopes to listen for interstellar radio transmissions from other cosmic civilizations. If ‘Oumuamua is in fact artificial, the reasoning goes, it might be transmitting or at least leaking radio waves. So far limited observations of ‘Oumuamua, using facilities such as the SETI Institute’s Allen Telescope Array, have turned up nothing. But this Wednesday at 3 p.m. Eastern time, the Breakthrough Listen project will aim the West Virgina-based 100-meter Green Bank Telescope at ‘Oumuamua for 10 hours of observations in a wide range of radio frequencies, scanning the object across its entire rotation in search of any signals. Breakthrough Listen is part of billionaire Yuri Milner’s Breakthrough Initiatives program, a collection of lavishly-funded efforts aiming to uncover evidence of life elsewhere in the universe. Other projects include Breakthrough Starshot, which intends to develop and launch interstellar probes, as well as Breakthrough Watch, which would use large telescopes to study exoplanets for signs of life. “With our equipment at Green Bank, we can detect a signal the strength of a mobile phone coming out of this object,” Milner says. “We don’t want to be sensational in any way, and we are very realistic about the chances this is artificial, but because this is a unique situation we think mankind can afford 10 hours of observing time using the best equipment on the planet to check a low-probability hypothesis.” Besides being simply a search for signs of aliens, Breakthrough Listen’s efforts could also narrow down the possibilities for ‘Oumuamua’s composition by looking for signs of water vapor sublimating from any sun-warmed ice lurking beneath the object’s red, desiccated surface. Avi Loeb, an astrophysicist and Breakthrough advisor at Harvard University who helped persuade Milner to pursue the observations, is similarly pessimistic about prospects for uncovering aliens. There are, he says, arguments against its artificial origins. For one thing, its estimated spin rate seems too low to create useful amounts of “artificial gravity” for anything onboard. Furthermore, ‘Oumuamua shows no sign of moving due to rocketry or other technology, instead following an orbit shaped by the gravitational force of the sun. Its speed relative to the solar system (about 20 kilometers per second) also seems rather slow for any interstellar probe, which presumably would cruise at higher speeds for faster trips between stars. But that pace aligns perfectly with those of typical nearby stars—suggesting ‘Oumuamua might be merely a piece of galactic “driftwood” washed up by celestial currents. Then again, Loeb says, “perhaps the aliens have a mothership that travels fast and releases baby spacecraft that freely fall into planetary system on a reconnaissance mission. In such a case, we might be able to intercept a communication signal between the different spacecraft.” Several years ago Loeb and two colleagues performed a speculative calculation estimating the interstellar abundance of ‘Oumuamua-sized space rocks based on the density of stars in the Milky Way and the vagaries of planet formation. That calculation, Loeb says, suggests the number of such space rocks is at least a hundred thousand times too low to account for ‘Oumuamua’s detection. Simply put, objects like ‘Oumuamua should be far too rare for our current telescopes to have any reasonable chance of spotting one. Newer studies gauging the odds find that for ‘Oumuamua’s detection to not be an astronomically unlikely fluke, there must be a sizeable population of such objects continuously passing through our solar system. This in turn suggests that more-capable future observatories, such as the Large Synoptic Survey Telescope, will find many more when they begin operations in the 2020s. “Typically in astronomy we don’t see things that are rare—if we see one, that means there’s a lot more out there,” says Breakthrough Listen’s lead scientist Andrew Siemion, who is also director of the Berkeley SETI Research Center. “So, while this is most likely a natural object, if we don’t eventually see any more, that would indeed be very strange and would increase interest from a SETI perspective.” Either way, Siemion says, “‘Oumuamua’s presence within our solar system affords Breakthrough Listen an opportunity to reach unprecedented sensitivities to possible artificial transmitters and demonstrate our ability to track nearby, fast-moving objects. Whether this object turns out to be artificial or natural, it’s a great target.” And if, against all odds, the Green Bank Telescope detects signals from this mysterious interstellar interloper—what happens then? Breakthrough Listen’s leaders assure us they would keep no secrets. First, the team at Green Bank would immediately re-observe ‘Oumuamua to confirm the signal. Next, they would reach out to astronomers around the world who could target the object with other radio telescopes. “We quite literally have a little Rolodex just for that,” Siemion says. “And at that moment this would become public. There’s no way to keep something like this a secret, because it requires us calling everyone we can. We tend not to ‘cry wolf’ about these things.” https://www.scientificamerican.com/...galactic-driftwood-seti-tunes-in-to-oumuamua/
Harvard Astronomer Still Believes Interstellar Object Was Alien Technology https://www.extremetech.com/extreme...eves-interstellar-object-was-alien-technology
