He worked for the Harvard College observatory, using a telescope with a grid etched into the glass eyepiece and sketching his astronomical observations on grid paper.
Trouvelot published 15 of his sketches as pastels. They're some of the best-preserved astronomical drawings of the 19th century.
Some illustrations are incredibly accurate, documenting moon craters and solar flares with scientific precision. Others are more creative and abstract, projecting Trouvelot's artistic expression onto the cosmos.
Today, sophisticated observatories and space telescopes snap images of the same celestial phenomena that Trouvelot captured more than 150 years ago. Here's how the 19th-century drawings compare to contemporary photos.
Etienne Léopold Trouvelot spent hours peering at planets, star clusters, and solar eruptions through a telescope with a grid etched into its glass eyepiece.
Three sketches of craters on the moon, produced in 1872 by Etienne Léopold Trouvelot.
Born in France in 1827, Trouvelot is most famous for bringing gypsy moths with him to the US. The invasive insect would go on to spread across North America, devouring more than 300 species of trees and shrubs.
In 1896, workers attempted to eradicate gypsy moth larvae from a large elm tree near Etienne Trouvelot's home in Malden, Massachusetts.
But Trouvelot was also an artist, and he got a job sketching astronomical observations at Harvard College's observatory. He drew what he saw through the gridded telescope.
People look at a drawing by Etienne Leopold Trouvelot called "Total Eclipse of the Sun" (1882) on July 1, 2019, at the Metropolitan Museum of Art in New York.
Over time, he turned many of those sketches into pastels and published 15 of them in The Trouvelot Astronomical Drawings Manual. This one shows sunspots.
These are dark patches of reduced temperatures that temporarily appear on the sun's surface.
More than 150 years later, photographic observatories on Earth and sophisticated telescopes in space are capturing the subjects of Trouvelot's drawings.
An active region on the sun, with dark sunspots.
NASA now has plenty of footage of flares and eruptions on the sun. Many of the explosions look just like Trouvelot's illustration.
A solar flare, captured November 1, 2014.
In reality, those green and purple ribbons aren't usually so linear.
The Aurora Borealis (Northern Lights) is seen over the sky near Rovaniemi in Lapland, Finland, October 7, 2018.
Alexander Kuznetsov/Reuters
His depictions of the sun and moon in particular were exquisitely detailed.
It looks different than today's photos, but that's probably because the Great Red Spot has been shrinking and getting more circular since astronomers began observing it about 150 years ago.
This Hubble Space Telescope view of Jupiter, taken on June 27, 2019, reveals the giant planet's trademark Great Red Spot.
But in recent decades, spacecraft like NASA's Hubble Space Telescope have gotten closer, sharper looks.
NASA's Hubble Space Telescope captured this image of Saturn on July 4, 2020. Two of Saturn's icy moons are visible: Mimas at right, and Enceladus at bottom.
Perhaps he caught the planet during a dust storm, but nothing on its surface today makes such a dramatic swirl.
The Hubble Space Telescope took this snapshot of Mars in the 1990s.
Looking beyond our solar system, Trouvelot spotted the Orion nebula - a dense cloud of gas that constantly forms new stars, 1,500 light-years from Earth.
NASA's Spitzer and Hubble Space Telescopes have captured Orion in three different light spectra, revealing gas layers of the stellar nursery.
A composite image from NASA's Spitzer and Hubble Space Telescopes shows the Orion nebula in visible, ultraviolet, and infrared light.
This image is color-coded for different molecules. The yellow smudge at the center is home to four massive stars, which heat and ionize hydrogen and sulfur gas in the surrounding cloud of green. The red and orange represent clouds filled with carbon-rich organic molecules.
Trouvelot also turned his telescope to the Hercules constellation to capture the cosmic glow of its dense star cluster.
Hubble can zoom in much closer, though. The result is an exquisite, colorful portrait of more than 100,000 stars at the cluster's center.
A Hubble Space Telescope composite image of the core of the M13 star cluster.
This triangular gleam appears on the horizon when dust orbiting the sun reflects its light towards the night side of Earth.
The zodiacal light in Skull Valley, Utah on March 1, 2021.
Trouvelot captured other celestial phenomenon that didn't require a telescope as well - like this comet that surprised the world in the summer of 1881.
Today, comets passing close to Earth are heavily documented by amateur and professional photographers.
Comet Neowise streaks past an Orthodox church over the Turets, Belarus, early Tuesday, July 14, 2020.
Trouvelot also sketched the paths of dozens of meteors - small space rocks that burn up in Earth's atmosphere as our planet passes through a field of space debris.
In the drawing above, he was likely sketching the Leonids during their peak in mid-November. The shower comes from debris left in Earth's orbit by the Tempel-Tuttle comet.
That drawing resembles long-exposure images that capture the dozens, or even hundreds, of shooting stars that streak across the skies every hour during meteor showers.
The Geminids meteor shower over the Mexican volcano Popocatepetl in the Mexican state of Puebla in the early hours of December 14, 2004.
Trouvelot also took an interest in eclipses. He sketched this partial lunar eclipse, when Earth's shadow blocked much of the sun's light from hitting the moon, in October 1874.
With modern cameras, the shadowed region of the moon during a partial eclipse appears much darker than in Trouvelot's pastel.
A partial lunar eclipse in Brasilia, Brazil, July 16, 2019.
The corona is only visible during a total solar eclipse. In photographs, it's more subtle.
The sun’s corona shines from behind the moon during a total solar eclipse on August 21, 2017.
But today's astronauts can capture a far more vibrant and breathtaking Milky Way from space.
Astronaut Scott Kelly posted this photo of the Milky Way, as seen from the International Space Station, on August 9, 2015.
