Artist's concept of Voyager 1 in interstellar space. Credit: NASA/JPL-Caltech
Edward Stone is retiring after 50 years as Project Scientist for the Voyager mission. The twin spacecraft revolutionized our understanding of our Solar System, and Stone was along for the ride every step of the way. Both spacecraft are still going, travelling deeper into interplanetary space, and still sending data home.
But after a long and rewarding career full of achievements and recognition, Stone is moving on.
Scott Alan Johnston (that’s me!) joined the Universe Today team just over a year ago. Since then, I’ve written over 50 space news stories for the website – time flies when you’re having fun! But when I’m not writing articles here on Universe Today, I’m a historian of science, and I recently released a new book about the history of timekeeping.
Have you ever wondered why we tell time the way we do? Well, history buffs, come along for a journey:
An unprocessed image from the WISPR instrument on board NASA’s Parker Solar Probe shows comet NEOWISE on July 5, 2020, shortly after its closest approach to the Sun. The Sun is out of frame to the left. The faint grid pattern near the center of the image is an artifact of the way the image is created. The small black structure near the lower left of the image is caused by a grain of dust resting on the imager’s lens.
Credits: NASA/Johns Hopkins APL/Naval Research Lab/Parker Solar Probe/Brendan Gallagher
Rome was the world’s first mega-empire. At its height it stretched from Western Europe to the Middle East, and over 50 million souls lived within its borders. Some historians think that number could’ve been way higher, up to 100 million.
Rome got its start in the mid-8th century BC. It took centuries for that small city to grow into the Roman Empire, which reached its peak around AD 100. A well-known cliche reminds us how long that took.
But the Roman Empire also took centuries to fracture and dissolve.
Image of the night sky taken at the European Southern Observatory’s Very Large Telescope in Chile. The Large and Small Magellanic Clouds are visible in the night sky. Credit: ESO, Y. Beletsky
The Magellanic Clouds are a pair of dwarf galaxies that are bound to the Milky Way. The Milky Way is slowly consuming them in Borg-like fashion, starting with the gas halo that surrounds both Clouds. They’re visible in the southern sky, and for centuries people have gazed up at them. They’re named after the Portuguese explorer Ferdinand Magellan, in our current times.
Fossil meteorites from the mid-Ordovician period, around 460 million years ago, indicate that Earth may have been hit by debris from an asteroid collision at that time. Image credit - Birger Schmitz
Comets visit the inner Solar System, and leave without saying goodbye. Maybe they leave a trail of dust behind, and when the Earth passes through it, we get a pretty light show in the night sky, in the form of a meteor shower. Likewise, asteroids frequently go whizzing by, though they don’t leave us with a pyrotechnic display.
Sometimes these rocky interlopers head straight for Earth. And when they do, the results can be cataclysmic, like when an asteroid struck Earth about 66 million years ago, wiping out the dinosaurs and 75% of life on Earth. Other times, it’s not quite as cataclysmic, but still devastating, like in about 2350 BC, when debris from a disintegrating comet may have caused the collapse of an ancient empire.
But regardless of the severity of any of these individual events, the conclusion is crystal clear: Earth’s history is intertwined with the coming and going of space rocks. The evidence is all around us, sort of.
GOES-17 Solar Ultraviolet Imager captures the Sun at different wavelengths. Credit: NOAA
Our Sun is the source of life on Earth. Its calm glow across billions of years has allowed life to evolve and flourish on our world. This does not mean our Sun doesn’t have an active side. We have observed massive solar flares, such as the 1859 Carrington event, which produced northern lights as far south as the Caribbean, and drove electrical currents in telegraph lines. If such a flare occurred in Earth’s direction today, it would devastate our electrical infrastructure. But fortunately for us, the Sun is mostly calm. Unusually calm when compared to other stars.
A frame from the first-ever film of a solar eclipse. Image Credit: British Film Institute, Royal Astronomical Society.
The first film of a total solar eclipse has been restored by specialists at the British Film Institute (BFI) and made available for viewing. The film was taken in North Caroline in 1900 by Nevil Maskelyne. Maskelyne was a British man who was a magician turned film-maker. He took the film as part of a Royal Astronomical Society (RAS) expedition.
John Glenn during his Friendship 7 flight. Credit: NASA
John Glenn always had the right stuff.
Glenn, the first American astronaut to orbit the Earth and a legendary figure around the world, has died. Glenn, 95, was the last remaining Mercury astronaut, the first group of US astronauts. He flew on Friendship 7 on Feb. 20, 1962, and later flew on the space shuttle in 1998 at age 77, becoming the oldest astronaut to fly in space. He also spent 24 years as a U.S. Senator from Ohio, and had a run for the presidency.
Astronaut John Glenn views stencilling used as a model to paint the words “Friendship 7” on his spacecraft. Credit: NASA
Glenn will always be remembered as the first American to orbit the Earth during those tentative, challenging, daring days when humans were just beginning to venture beyond the atmosphere that had nurtured them since the species began. – NASA obituary of John Glenn
“With John’s passing, our nation has lost an icon and Michelle and I have lost a friend,” said President Obama said in a statement. Obama added that Glenn’s flight pioneering flight “reminded us that with courage and a spirit of discovery there’s no limit to the heights we can reach together.”
“On behalf of a grateful nation, Godspeed, John Glenn.”
“John spent his life breaking barriers, from defending our freedom as a decorated Marine Corps fighter pilot in World War II and Korea, to setting a transcontinental speed record, to becoming, at age 77, the oldest human to touch the stars,” Obama said. “John always had the right stuff, inspiring generations of scientists, engineers and astronauts who will take us to Mars and beyond — not just to visit, but to stay.”
Glenn, born on July 18, 1921, was described in statement by his family and Trevor Brown, dean of the John Glenn School of Public Affairs at Ohio State University, as “humble, funny, and generous.” And “even after leaving public life, he loved to meet with citizens, school children in particular. He thrilled to music and had a weakness for chocolate.”
Glen married his childhood sweetheart, Annie Castor, and studied at Muskingum College in Ohio. Glenn became a Marine Corps fighter and flew 59 combat missions during World War II and 90 in the Korean War.
Glenn attended Test Pilot School at the Naval Air Test Center, Patuxent River, Md. After graduation, he was project officer on a number of aircraft. In July 1957, he set a transcontinental speed record from Los Angeles to New York — 3 hours and 23 minutes. It was the first transcontinental flight to average supersonic speed.
Glenn accumulated nearly 9,000 hours of flying time, about 3,000 of it in jets.
The ‘space race’ began when the Soviet Union launched the first satellite, Sputnik, in 1957. After a series of failures for the US space program, they finally succeeded on February 1, 1958 when Explorer 1 became the first US satellite in space.
But the main goal was to send humans to space.
The original seven astronauts pose with an Atlas model July 12, 1962. The ‘Mercury Seven’ astronauts pose with an Atlas model on July 12, 1962. Front row, left to right: Gus Grissom, Scott Carpenter, Deke Slayton and Gordon Cooper. Back row: Alan Shepard, Wally Schirra and John Glenn. Credit: NASA
In 1959, when the newly-formed National Aeronautics and Space Administration searched for the first Americans to fly in space, it focused on military test pilots. Glenn was in the select group – known as the Mercury 7 — who was chosen.
Glenn was assigned to the NASA Space Task Group at Langley, Va., in April 1959. The Space Task Group was moved to Houston and became part of the NASA Manned Spacecraft Center (which is now Johnson Space Center in Houston) in 1962.
While Glenn wasn’t chosen for the first Mercury space flight, his flight is well-remembered for being the first American to orbit Earth. But before any US astronauts could be launched into space, history was made on April 12, 1961 when Russian cosmonaut Yuri A. Gagarin became the first human in space when he completed his successful orbital flight aboard Vostok I.
Prior to Glenn’s 4-hour, 55-minute flight in Friendship 7, Glenn had served as backup pilot for astronauts Alan Shepard, the first American in space who flew on May 5, 1961, and to Virgil “Gus” Grissom, who followed Shepard on another suborbital flight on July 21, 1961.
On Feb. 20, 1962, Glenn launched from Cape Canaveral on Friendship 7, circling the earth three times. He became a national hero.
“Roger, liftoff, and the clock is running. We’re under way,” Glenn said after launch. After reaching space he said, “Zero-G and I feel fine. Man, that view is tremendous.”
Then-Senator Glenn joined the STS-95 Discovery crew in 1998, becoming the oldest person to fly in space at 77. Credit: NASA
Glenn was awarded the Presidential Medal of Freedom in 2012.
“The last of America’s first astronauts has left us, but propelled by their example we know that our future here on Earth compels us to keep reaching for the heavens,” Obama said.
Here are some tributes via Tweets for John Glenn:
We are saddened by the loss of Sen. John Glenn, the first American to orbit Earth. A true American hero. Godspeed, John Glenn. Ad astra. pic.twitter.com/89idi9r1NB
He inspired us to reach for the stars, and now we sadly return him to them. Let's honor his hope and dedicate ourselves to the good of all. pic.twitter.com/bz5fqQw05x
The Egyptian Pyramids; instantly recognizable to almost anyone. Image: Armstrong White, CC BY 2.0
The spread of metallurgy in different civilizations is a keen point of interest for historians and archaeologists. It helps chart the rise and fall of different cultures. There are even names for the different ages corresponding to increasingly sophisticated metallurgical technologies: the Stone Age, the Bronze Age, and the Iron Age.
But sometimes, a piece of evidence surfaces that doesn’t fit our understanding of a civilization.
Probably the most iconic ancient civilization in all of history is ancient Egypt. Its pyramids are instantly recognizable to almost anyone. When King Tutankhamun’s almost intact tomb was discovered in 1922, it was a treasure trove of artifacts. And though the tomb, and King Tut, are most well-known for the golden death mask, it’s another, little-known artifact that has perhaps the most intriguing story: King Tut’s iron dagger.
King Tutankhamun’s Golden Death Mask, one of the most stunning human artifacts in existence. Image: Carsten Frenzl, CC BY 2.0
King Tut’s iron-bladed dagger wasn’t discovered until 1925, three years after the tomb was discovered. It was hidden in the wrappings surrounding Tut’s mummy. It’s mere existence was a puzzle, because King Tut reigned in 1332–1323 BC, 600 years before the Egyptians developed iron smelting technology.
King Tut’s iron dagger was concealed in the wrappings surrounding the boy-king’s mummy. Image: Daniela Comelli/Polytechnic University of Milan
It was long thought, but never proven, that the blade may be made of meteorite iron. In the past, tests have produced inconclusive results. But according to a new study led by Daniela Comelli, of the Polytechnic University of Milan, and published in the Journal of Meteoritics and Planetary Science, there is no doubt that a meteorite was the source of iron for the blade.
The team of scientists behind the study used a technique called x-ray fluorescence spectrometry to determine the chemical composition of the blade. This technique aims x-rays at an artifact, then determines its composition by the spectrum of colors given off. Those results were then compared with 11 other meteorites.
In the dagger’s case, the results indicated Fe plus 10.8 wt% Ni and 0.58 wt% Co. This couldn’t be a coincidence, since iron meteorites are mostly made of Fe (Iron) and Ni (Nickel), with minor quantities of Co (Cobalt), P (Phosphorus), S (Sulphur), and C (Carbon). Iron found in the Earth’s crust has almost no Ni content.
Testing of Egyptian artifacts is a tricky business. Egypt is highly protective of their archaeological resources. This study was possible only because of advances in portable x-ray fluorescence spectrometry, which meant the dagger didn’t have to be taken to a lab and could be tested at the Egyptian Museum of Cairo.
Iron objects were rare in Egypt at that time, and were considered more valuable than gold. They were mostly decorative, probably because ancient Egyptians found iron very difficult to work. It requires a very high heat to work with, which was not possible in ancient Egypt.
Iron meteorites like this one would have attracted the attention of ancient Egyptians. This one is the Bendego meteorite from Brazil. Image: Jorge Andrade – Flickr: National Museum, Rio de Janeiro CC BY 2.0
Even without the ability to heat and work iron, a great deal of craftsmanship went into the blade. The dagger itself had to be hammered into shape, and it features a decorated golden handle and a rounded rock crystal knob. It’s golden sheath is decorated with a jackal’s head and a pattern of feathers and lilies.
Ancient Egyptians probably new what they were working with. They called meteorite iron from the sky in one hieroglyph. Whether they knew with absolute certainty that their iron meteorites came from the sky, and what that might have meant, they did value the iron. As the authors of the study say, “…our study confirms that ancient Egyptians attributed great value to meteoritic iron for the production of precious objects.”
The authors go on to say, “Moreover, the high manufacturing quality of Tutankhamun’s dagger blade, in comparison with other simple-shaped meteoritic iron artifacts, suggests a significant mastery of ironworking in Tutankhamun’s time.”
Dr. Robert H. Goddard and a liquid oxygen-gasoline rocket in the frame from which it was fired on March 16, 1926, at Auburn, Massachusetts. Image: NASA/Clark University Robert H. Goddard Archive
The invention of the rocket changed space science forever. The Universe could only be inspected from the surface of the Earth, with all that atmosphere in the way, until rockets were invented. And as far as the modern age of rocketry goes, it all started 90 years ago with Robert Goddard’s liquid-fuelled rocket.
Goddard was a dreamer. He envisioned rocket-powered spacecraft plying the solar system. Obviously, he passed away before interplanetary travel materialized, but his work on rocketry certainly laid the groundwork for that eventual achievement. The Goddard Space Flight Center is named after him, and it’s doubtful that any engineering or technology student in the world doesn’t know who he is.
Goddard’s first liquid-fuelled rocket was modest by today’s standards, of course. But he had to solve several technical challenges to achieve it, and his ability to solve these challenges led to not only this first flight, but to a total of 34 rocket flights in 15 years, from 1926 to 1941. His rockets reached the altitude of 2.6 km (1.6 miles) and speeds of 885 km/h (550 mph.) He also patented 214 inventions.
Goddard is considered the father of modern rocket science, but he is actually one of three men who are considered the main contributors to modern rocketry. Russian Konstantin Tsiolkovsky (1858-1935) and German Hermann Oberth (1894-1989) are the other founding fathers of modern rocketry.
Goddard didn’t invent rocketry, of course. The Chinese used rockets as far back as the 13th century, and rockets made appearances throughout history as weapons and fireworks. But Goddard’s success at liquid-fuelled rocketry, and the capabilities that came with it, is when rocketry really got off the ground. (Sorry.)
Nowadays, Goddard is understood to be a driven and highly-intelligent person, the type of person who is responsible for advancing science and technology. But back in his time, before he had successful flights, he and his ideas were ridiculed. Check out this criticism from the New York Times, January 13th, 1920:
“That Professor Goddard, with his ‘chair’ in Clark College and the countenancing of the Smithsonian Institution, does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react — to say that would be absurd. Of course he only seems to lack the knowledge ladled out daily in high schools.”
Stinging words, to be sure, but people who know anything about the history of science are familiar with this kind of condemnation of brilliant people, coming from those who lack vision.
Now of course, we have huge rockets. Great thundering beasts that lift enormous loads out of Earth’s gravity well. And we’re so accustomed to rocket launches now that they barely make news. But I always get a kick out of imagining what people like Goddard would feel if they were able to view a launch of one of today’s behemoths, like the Ariane 5. I’m sure his chest would swelled with pride, and he would be amazed at what people have accomplished.
But his vindication wouldn’t just come from the huge leaps we’ve made in rocket technology, and the huge rockets we now routinely launch. It would also come from this retraction, delivered decades too late but with class, by the New York Times, on July 17 1969, the day after Apollo 11 launched:
Further investigation and experimentation have confirmed the findings of Isaac Newton in the 17th Century and it is now definitely established that a rocket can function in a vacuum as well as in an atmosphere. The Times regrets the error.
