Sand- to boulder-sized particle of debris in the Solar System
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To get an idea of the energy involved in a rocket launch, the NASA Saturn V, moon rocket, fully fueled on the launch pad contained the chemical energy of 2,000 pounds of TNT. This old technology could carry us to Mars and back on missions that would last years. To cut the mission time, the risks, and the mass of supplies required for such a prolonged space mission NASA is looking at alternative means of rocket propulsion. Back in the 1950s NASA's project Orion was a study to investigate propelling a rocket by a series of atomic bomb explosions behind the vehicle. Now a safer and more gentle way of propelling a space craft with nuclear fission is being studied as the result of a NASA grant to BWX Technologies. The concept is to heat liquid hydrogen using a high temperature fission reactor furnace which would expel the gas at a high velocity producing the rocket's thrust. The process would be about twice as efficient in terms of thrust per pound of fuel when compared to burning a hydrogen and oxygen mixture. Since it is unacceptable to release trace amounts of radioactivity in the rocket's exhaust, engineers are investigating a technique developed by NASA in which the hydrogen exhaust is burned with oxygen to produce water which can be caught and decontaminated. Don't expect to buy a round trip ticket on a high speed fission powered rocket any time soon. However, in the long run nuclear technology could revolutionize the exploration and colonization of our solar system.
In April 2029 on one of the luckiest Friday the 13th in human history the 1500 ft by 500 ft asteroid Apophis will pass within 23,600 miles of the Earth's surface traveling at some 4.6 mi/s. This is extremely fortunate since an Apophis impact would release the energy of scores of nuclear weapons and cause wide spread devastation. NASA's OSIRIS-APEX will become the companion of the potentially hazardous asteroid Apophis on 5 June 2029,
Eighteen hours before my Catalina Sky Survey teammate Rose Matheny first spotted a small space rock with our Schmidt telescope on Mt. Bigelow, Arizona it had passed less than the Earth's diameter from the surface of our planet. Rose was able to discover this Smart Car sized space rock after it moved out of the Sun's glare. At this point it was about the Moon's distance from her and was traveling away at 3.4 mi/s. After Rose posted her discovery observations on the Minor Planet Center's Near Earth Object Confirmation page, for the next 24 hours it was tracked by telescopes in Spain, Illinois, and Arizona. Scientists at the Minor Planet Center used these data to calculate it's orbit around the Sun, estimate it's size and give it the name 2017 UJ2. This small asteroid had come near the Earth in 1978 but was invisible to the technology which astronomers had available at the time. 2017 UJ2 will not come close enough for us to detect in the foreseeable future, however, there are likely to be tens of millions of others like it which can come close to Earth. A small asteroid the size of Rose's discovery is likely to enter our atmosphere at least once a year and explodes at about 4 times higher than airliners fly. If such an event happened at night and you were lucky enough to see it you would be treated to a fantastic light show. If you are as lucky as a power ball winner you might even be able to find a piece of it on the ground.
The Earth's atmosphere does a good job of protecting humanity from space weather, however, occasionally a major event does break through our shield and gets our attention. Tree rings and ice cores have recorded past space weather events thousands of time larger than which have occurred in the modern age. investing in research seems wise.
In an area which is about 1/400th of the entire sky, the NASA Kepler spacecraft has discovered 30 Earth like planets which are likely to have liquid water on their surfaces orbiting distant stars. These planets are likely to represent a tiny sample of the habitable planets which exist in the Milky Way. In spite of our efforts to find them, the question remains where are the alien civilizations? In a recent talk given at the Division of Planetary Sciences meeting Dr. Alan Stern of the Southwest Research Institute suggests that perhaps the majority of worlds with biology and intelligent civilizations exist on interior water ocean worlds where their existence is hidden by the thick layers of rock and ice which separate them from the hostile vacuum of space. We know that in our solar system alone the moon of Jupiter Europa, Saturn's moon Enceladus, and perhaps several other small worlds are likely to have oceans of nutrient rich liquid water covered by a thick layer of rock and ice. We also know that Whales and Dolphins have larger brains than humans, communicate with each other, and exhibit other forms of intelligence. Advanced civilizations existing in ice covered seas may know little of the greater Universe, may find it difficult to consider transporting enough water to travel beyond their worlds, and may not think that it is possible to communicate with others of their kind who are similarly hidden under miles and miles of radiation absorbing ice and rock.
Around the world those who value the natural night sky are evaluating the effects of light pollution. In addition to impairing astronomy and star gazing the past 100 years of increasing light pollution is proving to be harmful to human health and the natural world upon which we all depend. The purpose of the Dark Sky Network is monitor and facilitate the mitigation of the harmful effects of light pollution.
On it's gravitational leash, Earth's pet space rock, 2016 HO3, accompanies us at a distance of between 38 and 100 times the Moon's distance from Earth as we both travel about the Sun. As this tiny asteroid orbits the Sun it spends about half of it's time inside the Earth's orbit where it moves faster and passes ahead of us and the other half of it's yearly path outside of our orbit which causes it to lag behind our home planet. Since it's discovery little has been known about Earth's pet space rock leaving some to speculate that perhaps it is an old rocket booster or other piece of space junk. To answer this question, Dr. Vishnu Reddy of the University of Arizona's Lunar and Planetary Laboratory headed up a team of astronomers who used the University of Arizona's Large Binocular Telescope and the Discovery Channel's Telescope to determine some of it's properties. This team of researchers found that 2016 HO3 is indeed a natural object about 100 to 300 feet in diameter, rotates about once every 28 minutes, and is made of material similar to meteorites which have landed on Earth. Our pet space rock, 2016 HO3, has apparently been in it's present relationship to Earth for a hundred years and is likely to remain so for hundreds of years to come. Even though 2016 HO3 is not gravitationally bound to the Earth, the combination of the Sun's and Earth's gravitational pulls keeps it relatively near making it easy to reach and thus is an ideal candidate for visits by human or robotic spacecraft.
Since in its early history the Earth's surface was hot and lifeless it is likely that asteroids formed in the same era as Bennu delivered the raw materials for life when they impacted our home planet long ago
On Earth, human life is enabled by plants which provide us with calories, vitamins, fuel, medicines, and oxygen to breathe. In addition, recent scientific studies indicate that plant cultivation reduces anxiety and depression and has a positive influence on diabetes, heart disease, obesity, and longevity. Perhaps this is the reason that 80% of the cultivated plant species on planet Earth are not used for any food related purpose. On long duration space missions astronauts live in close quarters isolated from the natural world where the basic activities like eating, sleeping, and attending to bodily functions are difficult and stress producing. Recent research conducted on the International Space Station suggests that space gardening helps astronauts to cope with the sterile space craft interior, allows them to combat boredom, as well as some of the other negative psychological effects of their long period of confinement. Specific examples of International Space Station gardens include astronaut Scott Kelly's first zinnia to bloom in space and astronaut Peggy Whitson's small crop of space soybeans. For many thousands of years people making long journeys have taken plants for food and recreation with them. It is likely that when humans travel to Mars they will continue this practice. The plants that Mars explorers take with them will provide a source of fresh fruits and vegetables , fresh air to breathe, and perhaps a psychological benefit that is crucial to the success of their mission.
In the distant past things in our solar system were very much more wild and violent than they are today. 4.5 billion years ago a Mars sized object called Theia impacted Earth producing our Moon. Scientists are able research this event using the current chemical compositions of the Earth and Moon.
In less than 24 hours, while observing with the Catalina Sky Survey's 60 inch telescope on Mt. Lemmon, Arizona , I discovered two 25 foot diameter space rocks that theoretically can pass less than a quarter of the Moon's distance from us. After I posted my discovery observations on the Minor Planet Center's Near Earth Object Confirmation page one of them received immediate attention, as an incoming object, and was tracked by observers at 14 different observatories around the world. Scientists at the Minor Planet Center used these data to calculate it's 926 day orbital path around the Sun, estimate it's size, and give it the name 2017 TH5. 36 hours after I first spotted 2017 TH5 streaking through the night sky it came to less than 60,000 miles from the surface of our planet traveling at 7.6 miles per second. 8 hours and 49 minutes later it passed less than half a lunar distance from the surface of our moon. If 2017 TH5 would have been on an impact trajectory with Earth humans would have had time to prepare for a spectacular light show. Approximately once every 5 years a tiny asteroid like 2017 TH5 enters our atmosphere exploding at an altitude about 3 times higher than airliners fly releasing the energy of about 5,000 tons of TNT. Asteroid hunters are well on our way towards being able to issue a warning to stay away from doors and windows should a small space rock be discovered to be on an impact trajectory with planet Earth.
My Catalina Sky Survey teammate David Rankin was asteroid hunting in the evening twilight with our 60 inch telescope on Mt. Lemmon Arizona when he spotted an unknown object in the constellation of Lyra. The largest telescopes on Earth will likely track David's discovery until it becomes too faint to observe in 2027 and catch it again when it again becomes bright enough to track in 2050. Fortunately it is extremely unlikely that it will strike Earth when it again comes close to our home planet in 2052.
New Zealand's 4.5 million people are concentrated in three major population centers which to various degrees suffer from the modern plague of light pollution. However, most of New Zealand's large rural areas and land reserves, covering an area as large as the UK, have unpolluted natural night skies. A completely unique place to experience New Zealand's natural night sky is the Aotea [ Ah - yoh - tee - ah]-Great Barrier Island International Dark Sky Sanctuary. It encompasses New Zealand's, 110 square mile, sixth largest island, which is located about 62 miles from central Auckland. It is easily accessible by boat or a short airline flight. The island's 1000 residents are employed by agriculture and tourism. They value the natural night sky and function without externally generated electricity or street lights and fully support the preservation of their prestine night sky. In the daytime Great Barrier Island offers wonderful beaches and hikes. When the sun sets the night sky becomes alive with its own natural lights. Night sky measurements by Auckland Astronomer Nalayini [ Na - laa - i - ni] Davies and her collaborators have proved that the Great Barrier Island's natural night skies are second to none on planet Earth. Using the unaided eye, a set of binoculars, or a small telescope an observer on the Great Barrier Island is treated to spectacular views of the center of the Milky Way, the clouds of Magellan the nearest galaxies to us, the nearest stars, as well as numerous star clusters, meteors, comets, and other wonders of the natural night sky. Perhaps this unique spot deserves a place on your bucket list.
It is possible the object creating the Tunguska event in Russia 1908 which knocked down 80 million trees over an area about twice the size of New York City was a fragment of a comet or asteroid. The International Asteroid Warning Network 2025 campaign to track Comet 3L/Atlas prepares the worlds observatories for the eventual time when a comet fragment has our number on it.
In November of 2006, University of Arizona's Spacewatch astronomers on Kitt Peak discovered a faint moving point of light in the night sky which appeared to be a garden variety main belt asteroid orbiting the Sun between Mars and Jupiter. The Minor Planet Center calculated it's orbit and gave it the name 2006 VW139. Five years later when it again moved closest to the Sun the Pan-STARRS group in Hawaii discovered that 2006 VW139 is surrounded by a gas cloud like a comet and it was given a comet designation, 288P. My Catalina Sky Survey teammate Steve Larson is a member of the team of astronomers who use the Hubble Space Telescope to observe asteroids which have comet like burps. Observations by the Hubble Space Telescope between August 2016 and January 2017 clearly show 288P to be two similar, mile diameter, asteroids orbiting each other about 60 miles apart, surrounded by a gas cloud, as they move about the Sun. The Hubble team estimates that about 5,000 years ago this strange object was formed when a rapidly rotating comet nucleus came apart into two large pieces. It's gas cloud is likely to come from volatile ices like carbon dioxide and water vapor which were liberated by solar heating. Objects like this one are very interesting since they may have had a role in bringing water to a bone dry Earth in the early days of our solar system.
My Catalina Sky Survey teammate David Rankin was asteroid hunting in the evening twilight with our 60 inch telescope on Mt. Lemmon Arizona when he spotted an unknown object in the constellation of Lyra. The largest telescopes on Earth will likely track David's discovery until it becomes too faint to observe in 2027 and catch it again when it again becomes bright enough to track in 2050. Fortunately it is extremely unlikely that it will strike Earth when it again comes close to our home planet in 2052.
Many people in our modern world rarely if ever experience night vision. To achieve this interesting state of sensory awareness you cannot look at your cell phone or any other source of bright light for 30 to 45 minutes. Your night vision comes about over time because the rod sensors in the retina of your eye undergo a chemical change when they are placed in total darkness. The process starts immediately but takes 20 to 30 minutes to get 80% of maximum sensitivity. The night vision process can be reversed in seconds by exposure to a bright light. In it's most sensitive state your eye can function with a billion times less light than is present in strong sunlight enabling you to see a candle flame from 1.6 miles away.
It is possible the object creating the Tunguska event in Russia 1908 which knocked down 80 million trees over an area about twice the size of New York City was a fragment of a comet or asteroid. The International Asteroid Warning Network 2025 campaign to track Comet 3L/Atlas prepares the worlds observatories for the eventual time when a comet fragment has our number on it.
Venus and Earth are similar in size, composition, density, and mass. Unfortunately, our sister planet Venus is an example of a place where green house gases have created an extreme situation. Venus's thick carbon dioxide atmosphere has a surface pressure 90 times that of Earth. It would crush a submarine. Additionally, the thick atmospheric blanket holds in the heat causing Venus's surface temperature to be 864 F, hot enough to melt lead.
Just before noon on September 1st of 1859 Richard Carrington and Richard Hodgson were making sketches of clusters of sunspots when they were nearly blinded by an intense solar flare. 17.6 hours later a geomagnetic storm thought to be caused by a solar coronal mass ejection traveling at some 1,500 miles per second slammed into the magnetic field surrounding our home planet. We missed being hit with a such large coronal mass ejection by only 9 days in July of 2012. Next time we might not be that lucky.
Dr Lance Benner of NASA's Jet Propulsion Laboratory headed up a team of scientists who used the 70 meter antenna at NASA's Goldstone Deep Space Communications Complex to bounce RADAR beams off of the asteroid Florence as it made a close approach to Earth in September of 2017. The RADAR images these researchers obtained reveal that Florence consists of a 2.8 mile diameter primary asteroid which is orbited by two small moons. Florence's two satellites appear to be between three hundred and a thousand feet in diameter and orbit the main asteroid in about 8 and 24 hours respectively. Florence is rare since there are only two other triple asteroid systems among the 16,000 Earth approaching asteroids which asteroid hunters have discovered. We would know more about Florence if Hurricane Irma had not prevented astronomers from using the giant Arecibo RADAR Dish in Puerto Rico to study it. Our curiosity will have to wait since Florence will not come very close again until September 2, 2057.
The Dark Energy Camera on the National Science Foundation's Blanco 4-meter telescope on Cerro Tololo in Chile is taking near Sun twilight images to search for asteroids, hidden in the glare of our Sun, sneaking up on home planet.
At about 2AM on July 18, 2011 several people in near Tata, Morocco saw a bright fireball which was described by one of them to be initially yellow, then turned green, and finally exploded into several pieces producing two sonic booms. In October of 2011 desert wandering nomads began finding very fresh looking dark fusion-crusted stones which were radioactively dated by Dr. John Duke of the University of Alberta to be less than 5 years old. In total 15-24 lbs of meteorites consistent with a very recent fall were found in a strewn field, were whisk away to receive high prices from collectors, and named after the town of Tissint [tee.seent] about 30 miles from their discovery location.
My Catalina Sky Survey teammate Vivian Carvajal was asteroid hunting in the constellation of Eridanus with the 90 inch, University of Arizona's Bok telescope on Kitt Peak when she was treated to an amazing sight. Comet COMET 240P/NEAT with a small version of itself cruising along beside it.It is virtually impossible to predict if Vivian's fragment 240P-B will survive to make another approach to the Sun in 2033 or so.
Meteors, shooting stars, or falling stars are different names for the streaks of light in the night sky which are in reality the dying embers of tiny asteroids. These small interplanetary travelers were speeding along at between 7 and 44 miles per second when they entered the Earth's atmosphere. In space, they are called meteoroids and typically ranged in size from that of a grain of sand to perhaps ones as big as of a piece of driveway gravel. Large space pebbles can produce fireballs which are brighter than the planet Venus. Most meteors burn up 50-70 miles above you, however, a very few of them produce fragments which fall to the Earth's surface. In rare occasions meteor observers are able to walk up to such a fallen space rock which is called a fall. The best time to view meteors is generally after midnight on a clear, moonless night. You will see many more meteors in a rural area than under city lights. On nights not during a meteor shower, you may expect to view sporadic meteors at the rate of between 2 and 16 per hour. Some meteor showers produce more than 100 events per hour. Rarely you will have a chance to view a meteor storm which will give you the feeling that you are seeing the Earth move through space. In 1966 one of these storms produced a WOW inspiring 40 meteors per second. During the year, there are a dozen major meteor showers. Check out the International Meteor Organization Calendar for a complete listing of the dates of meteor showers as well as how bright the moon will be on those dates. Happy viewing.
On a busy night of asteroid hunting with the 90 inch, University of Arizona's Steward Observatory Bok telescope on Kitt Peak in Arizona, my Catalina Sky Survey teammate Vivian Carvajal discovered 13 new Earth approaching objects. One of them now known as 2025 TF immediately got her attention as it streaked through the constellation of Pegasus. Another space rock 2020 VT4 came about 30 miles closer to the surface of our home planet giving 2025 TF second place as a grazing non impactor.
Jupiter has been observed throughout human history and is so bright that you can even spot it under the artificial light dome of one of our cities. Even so it is less than 40 years ago that we were first able to view Jupiter in detail as the Voyagers streaked by it. Jupiter contains more than twice the mass of all of the other planets, dwarf planets, asteroids, and comets in our solar system combined. Eons ago, our solar systems very own giant planet, Jupiter, appears to have cleared out the inner solar system leaving enough rocky debris to form Mercury, Venus, Earth, and Mars. Without Jupiter's action our solar system is likely to have turned out like the more than half of the planetary systems which we have found which consist of non-inhabitable super Earth sized planets orbiting closely about their host stars. In terms of the defense of planet Earth from impacting objects, Jupiter is a mixed blessing. It apparently deflects some of the long period comets out of Earth impacting orbits while sending other asteroids and comets our way. In 1770 a small comet came in from the outer solar system and passed near Jupiter. This encounter sent it straight towards Earth. Fortunately this celestial visitor missed humanity by about a million miles. After two orbits of the Sun this small comet once again passed near Jupiter and was ejected from the solar system. Look up where to find Jupiter on the internet and observe it. Jupiter is an awesome sight in binoculars or a small telescope. As you view this gas giant think about the fact that it is likely the reason you have a place to stand and air to breathe.
In a recent 60 day period asteroid hunters tracked 24 space rocks which came closer than our Moon. My team the University of Arizona's Catalina Sky Survey operates 5 telescopes in the mountains around Tucson, Arizona. Our goal is to find objects like 2025 RM1 which are on an impact trajectory with our home planet in advance so that people in the effected area can be warned to stay away from doors and windows.
Throughout history small close approaching space rocks have been a part of our environment. Now, thanks to improved telescopes and cameras, asteroid hunters are routinely discovering these small asteroids as they pass closer than the Moon is to us. Since these tiny asteroids are only bright enough to detect for a few days out of their long, many month duration paths about the Sun, astronomers have had difficulty in determining how many of these small space rocks may exist in near Earth space. This effort received more emphasis when a house sized space rock exploded over Chelyabinsk, Russia in 2013 releasing about 10 times the energy of the Hiroshima atomic bomb. Although this asteroid was tiny compared to the one that ended the dinosaurs rule of the planet, the air blast the Chelyabinsk bolide produced caused nearly 1,500 human injuries and damaged more than 7,000 buildings. In a 2017 paper in the Astronomical Journal, Dr. David Trilling of Northern Arizona University and his group of researchers present data from the Blanco 4 meter telescope at the Cerro Tololo Inter-American Observatory in Chile which they use to estimate that there are approximately 3.2 million Earth approaching asteroids similar in size to the Chelyabinsk impactor. My team the Catalina Sky Survey uses 4 telescopes, 24 nights per month, in the mountains north of Tucson, Arizona with the goal to provide warnings for people to stay away from doors and windows should a Chelyabinsk sized space rock be on an impact trajectory with planet Earth.
Dr Uisdean Nicholson from Heriot-Watt University and his team of 9 co-authors analyze 3D seismic imaging and drill cuttings from a 1980s oil well to make a convincing case that the Silverpit crater was produced by a the impact of a 1.5 football field diameter asteroid approximately 45 million years ago.
Humans have a long history of partnerships with a variety of micro organisms. Although the proportions vary widely with individuals, recent scientific estimates suggest that a typical human being has approximately the same number of bacteria and other microbes as they do actual human cells. Now it appears that a partnership with yeast and algae will enable spacefaring humans to use their waste products to produce food and plastics during long duration space flights. Dr. Mark Blenner of Clemson University leads a research group developing strains of yeast which obtain their nitrogen from untreated urine and their carbon dioxide from exhaled breath or the Martian atmosphere which has been converted into yeast food by algae. One of Blenner's yeast strains produces omega-3 fatty acids which are essential for heart, eye, and brain health while another strain of yeast has been engineered to produce polyester polymers which could be used by 3D printers to produce plastic tools and other useful devices. In the future research Blenner's team will focus on increasing the output of these tiny beasts to the point that they will generate useful amounts of nutrients and plastics from astronaut's waste products. This new research when added to the fact that on the International Space Station space travelers now routinely drink recycled water from their urine, sweat, and showers moves us closer to the day when space travelers literally use and reuse every atom that they lift from the Earth's surface enabling journeys that may last for years. The flip side of our partnership with microorganisms is that it is extremely difficult to protect the worlds we explore from a microorganism invasion which would threaten their home grown biology.
On a recent clear night my Catalina Sky Survey teammate Hannes Groller was asteroid hunting with the Steward Observatory 90 inch Bok telescope on Kitt Peak, Arizona when he discovered 8 natural visitors to our neighborhood. Telescopes around the world began to track and determine the natures these asteroids. Six of Hannes's discoveries are classified as Near Earth Objects while the other two are more distant Mars crossing asteroids
The moon cycle from new moon through full moon and back to new moon again was used by many nations to regulate their activities and forms the basis of the Islamic lunar calendar. A calendar based on the first visibility of the lunar crescent is difficult to predict in advance since this observation depends on the clarity of the atmosphere and other local conditions. The interesting observational problem of when it is possible to spot the new moon has been analyzed in the scientific literature as an aid to historians who are seeking to interpret the writings of ancient civilizations.
Scientists are using many approaches to understanding the nature and history of 3I/Atlas the third known interstellar traveler in the night. At a hyperbolic velocity of 130,000 mph it is the fastest interstellar visitor ever measured.
Finding a meteorite that has traveled billions of miles through space to reach it's present location is exciting. It might even be worth real money.
Obtaining accurate data on the Earth's climate and how it is changing is vital to inform agriculture , insurance risks, business planning, disaster preparedness, financial investments, wild fire mitigation, and national security. The USA should not be flying blind and relying on Europe and China for the data we need.
Friday the 13th appears to continue to be a lucky day for the human race. When astronomers first discovered Apophis in 2004 it appeared possible that this 3 million ton, 1,200 foot diameter asteroid traveling at 8 mi/s could impact our planet creating a crater a several miles diameter and more than a half mile deep. Additional observations over the years have eliminated this possibility as Apophis streaks by closer than the communications satellites on that lucky Friday the 13th. Further, current calculations have reduced the chances of Apophis colliding with Earth in the next 100 years to about one in 100,000. However, over the millennia Apophis is likely to strike the Earth as does one it's size once every 100,000 years or so.
The Lagrange point L4 is 60° ahead of Mars whereas L5 is 60° behind Mars on the red planet's orbital path about the Sun. An object placed at either of these locations is trapped gravitationally and is likely to remain there indefinitely. The Mars L4 and L5 locations could provide a permanent place for staging and resupply missions to Mars and would give humans a different view of space weather and its effects on our home planet.
To reach the vicinity of the nearest star, 24 trillion miles away, in less than 20 years, an interstellar space probe would have to travel at a substantial fraction of the speed of light. Newton's laws of motion, published 300 years ago, predict that the greater the mass of an object the greater is the force required to increase it's velocity. In order to alleviate the need for the virtually unaffordable amount of energy required to accelerate a normal sized spacecraft to a speed of 20% of the speed of light, the Breakthrough Starshot program has funded the creation of 'Sprite' , the world's smallest spacecraft. About the size of a saltine cracker and having a mass of less than 2 dimes, the single-board Sprite spacecraft has all the essentials; solar panels, computing electronics, thermometers, gyroscopes, radio communication equipment and more. Working prototypes have been launched into Earth orbit by the Indian Space Research Organization attached to the Italian Max Valier and Latvian Ventra satellites. One of them has sent back signals which have been received by Cornell University's ground station. Dr. Zac Manchester who started the Sprite Spacecraft program while earning a PhD at Cornell University envisions using tiny spacecraft to explore near Earth Space as well as asteroids and moons in our solar system. In the future, fleets of the decedents of Sprite could be sent to explore intriguing planets in nearby alien solar systems. These tiny explorers will be propelled by high power Earth bound lasers directed at their solar sails and could reach and explore distant planets in a reasonable amount of time.
50 years ago scientists found that Chlorofluorocarbons or CFC chemicals in widespread use in refrigeration, air conditioning , and hair spray were beginning to damage the ozone layer in the Earth's stratosphere which blocks harmful Solar UVB radiation from reaching the surface. The world wide response was the Montreal Protocol banning these chemicals from being released into the atmosphere. It saved millions of humans from dying of skin cancer. Satellite ashes are a new threat to the protective ozone layer.
Looking at the stars on a clear dark night, far from the artificial air glow humanity creates, have you ever wondered what it would be like to travel in truly deep interstellar space? 40 years after their launches in 1977, your representatives, the twin Voyager 1 and Voyager 2 spacecraft are in the vast space between the stars in our Milky Way galaxy. Aboard each Voyager is a Golden Record time capsule which expected to last billions of years. This message from all of humanity is inscribed with greetings from Earth as well as sounds, images, and a decoding key which will enable any intelligent aliens which find a Voyager to discover who made it and where it came from.
The planets, millions of asteroids, tens of thousands of comets, distant icy worlds, and countless other bits and pieces of material orbit the Sun. A group of such co-orbiting objects is called the Taurid complex or swarm. It consists of Comet 2P/Enke, a number of near Earth asteroids, and the meteor stream which produces the Taurid meteor shower every October and November.
When the Japanese spacecraft Hayabusa [Hi ya Boo sa] visited the near Earth asteroid Itokawa in 2005 it found this 2000 foot by 800 foot elliptical world to have a variety of surface features. Instead of being a solid object like some asteroids, Itokawa is a rubble pile of boulders and pebbles held together by it's tiny gravity. The total volume of pebbles seems to be comparable to the volume of large rocks and boulders which make up Itokawa , however, the depths of the pebbles or their concentration in the center remains unknown. Given this uncertainty, this asteroid appears to be made up of a million times more small particles than larger ones.
Astronomers have discovered some 1.4 million asteroids. Approximately 35,000 of these space rocks come near Earth. Less than 40 of them are classified as being Atira asteroids whose orbits lie entirely within the Earth's orbit about the Sun. Only one of these, asteroid number 594913 named 'Ayló'chaxnim (eye-LAW-chax-nim ) has an orbit which is entirely within the orbit of the planet Venus.
The lunar roving, battery powered, 4 wheel drive "Moon Buggy" allowed astronauts on Apollo 15, 16, and 17 to travel 8 mph on the lunar surface with a maximum range of approximately 4.7 mi. Some of the rocks that these space travelers brought back, from the tiny area they were able to visit on the Moon, contained volcanic glass beads with trace amounts of trapped water inside of them.
Dr. Bill Cooke of NASA's Meteoroid Environment Office reports that on June 26, 2025 shortly after noon a beachball sized meteoroid traveling at approximately 30,000 miles per hour broke up about 27 miles above the town of West Forrest, Georgia.
Martian Trojan asteroids have stable orbits around the Sun, leading and trailing the red planet by 60 degrees, where the Sun's and Mars's gravity are balanced. For some time astronomers have considered it unlikely that these asteroids wandered in from the asteroid belt. Recently, Dr. David Polishook of the Weizmann Institute of Science in Israel led a group of researchers who published a paper in the journal Nature Astronomy which sets forth evidence that a group of 7 Martian Trojan Asteroids were blasted from the Martian surface when a large asteroid impacted the red planet early in the history of the solar system. The impact more than 4 billion years or so ago which blasted loose a mile diameter chunk of Mars and gave it a speed of the more than the 3 mi/s required to escape the red planet gives us an insight into the level of violence which occurred before our solar system came into it's present relatively calm state.
Amazingly, nature occasionally sends an interstellar traveler through our solar system for us to observe. The third such object that astronomers have discovered coming into our solar system from truly deep space is 3I/ATLAS. It was discovered as it streaked towards the inner solar system at 130,000 miles per hour by the ATLAS team's 20 inch telescope in Chile and was quickly tracked by telescope around the world.
The Sun is our very own well behaved star. It rises and sets in our sky every day and powers and makes possible all life forms on planet Earth. A new appreciation for our Sun is growing as we learn more about other suns and their families of planets. The Trappist-1 system of 7 planets orbits a dim M type red dwarf star about 40 light years away in the constellation of Aquarius.Recently, Dr. Manasvi Lingam and Dr. Abraham Loeb of Harvard University have calculated the likelihood that planets orbiting red dwarf stars are able to possess an atmosphere conducive to life. They report, in a recently published a paper in the International Journal of Astrobiology that the planet Trappist 1-e is more than 100 times less likely to be habitable than is the Earth. Another group from Harvard and the University of Massachusetts at Lowell, headed up by Dr. Cecilia Garraffo also find the Trappist-1 planets to be a tough place to live. These researchers add that the close proximity of these planets to their host star put them at risk of having their atmospheres stripped off by high stellar winds and their surfaces bombarded with high energy particles and electromagnetic radiation. Go outside today and enjoy some gentle sunshine from our well behaved star.
On a a short June night my Catalina Sky Survey teammate Greg Leonard was observing with our 60 inch telescope on Mt. Lemmon, Arizona in the constellation of Ursa Major when a relatively bright fast moving point of light appeared in a set of his images. Even though on its current path Greg's discovery, 2025 MM89, has virtually no chance of impacting our home planet asteroid hunters will continue to track it to make sure it doesn't become a threat as it passes other objects in space.