Astronomers, particularly those working on NASA’s program to study near-Earth objects, have been carefully scanning the night sky for decades. Their main goal is to search for potentially hazardous asteroids that could cause catastrophic damage to our planet. Fortunately, we have not yet found a single such object: according to NASA, none of the known asteroids will pose a threat to Earth for at least the next hundred years.
It might seem like all those hours of constant surveillance were a waste of time, since we never actually had to call on Bruce Willis to save humanity from Armageddon. However, in addition to planetary safety, this ongoing monitoring provides us with invaluable insights into the Solar System. What’s more, a new study by Marcelo de Oliveira Souza of the State University of Rio de Janeiro North shows that this data has another benefit: it helps identify the fastest routes to other planets.
Useful mistakes
When astronomers first spot a new asteroid, the calculations of its orbit are usually very imprecise. A prime example is the asteroid 2024 YR4. Initially, early observations caused quite a panic, suggesting a 3.1% probability of a collision with Earth. Subsequently, the risk was reduced to nearly zero, but a new estimate emerged: a 4.3% probability of a collision with the Moon. Eventually, once the orbit was refined, that risk disappeared as well.
The problem is that initial observations are always subject to significant error. Astronomers simulate an object’s trajectory immediately after its discovery, and only over time, as new data becomes available, its actual orbit takes shape.
That’s where the real fun begins. When the near-Earth asteroid 2001 CA21 was first discovered and its initial trajectory was reconstructed, it turned out that it was set to take a very “convenient” journey. Its presumed trajectory crossed not only Earth’s orbit but also Mars’s orbit. Although the asteroid’s actual trajectory was later refined significantly and turned out to be different, Oliveira realized that these “erroneous” calculations could be extremely useful.
As the scientist explains, he deliberately chose this early solution for analysis because such a preliminary orbit has ideal geometry: it intersects or comes very close to the orbital paths of both Earth and Mars at the same time.
Mission 2031
Oliveira decided to see if this theoretical asteroid trajectory could be used as a template for planning actual missions to Mars. He analyzed three possible launch windows in 2027, 2029, and 2031. These are periods of so-called opposition, when Earth is positioned exactly between the Sun and Mars, and the distance between the planets is at its shortest—this happens approximately once every 26 months.
The study showed that only the 2031 configuration fully met all requirements. In this window, the scientist identified two closed-loop flight architectures for the “Earth–Mars–Earth” route:
- Ultra-short mission: lasts only 153 days (33 days for the flight to Mars, 30 days in orbit around the planet, and 90 days for the return trip).
- Optimal mission: 226 days (56 days of travel to Mars, 35 days in orbit, 135 days for the return trip)
Both options allow the spacecraft to travel to Mars and return in significantly less than one Earth year.
A new map of interplanetary travel
Although the prospect of such rapid flights is impressive on its own, Oliveira Souza’s main goal was to demonstrate a unique concept: early data on asteroids and their imprecisely predicted paths can serve as ready-made templates for developing space missions, since early calculations of the orbits of small bodies may conceal natural heliocentric geometries. This approach establishes an entirely new navigational framework that will enable astronomers in the future to identify similar optimal routes among the orbits of other near-Earth objects.
According to iflscience.com
