NASA / JPL-Caltech
When Neil Armstrong set foot on the moon 50 years ago, it was an inspiring moment for people around the world.
But another type of explorer is at the root of much of the modern enthusiasm for space exploration.
"Since the time of Apollo, the robots that have traveled the solar system have been the greatest adventures in space," says Emily Lakdawalla, a planetary evangelist of the Planetary Society.
By "these robots", Lakdawalla refers to the various robotic probes that flew over planets, moons and asteroids – in orbit or landing.
Humans continue to explore the space. The International Space Station is a remarkable equipment. Humans have lived there for almost two decades. But as incredible as the space station is, its enthusiasm is relatively modest.
Lakdawalla says it would be inspiring to see an astronaut land on Mars, but in the meantime, inspiration comes from NASA rovers.
"It's very easy to anthropomorphize and imagine rolling on the surface of Mars," she says. "It's really not an exaggeration to imagine ourselves instead of these robots exploring the solar system."
Millions of people around the world have enjoyed watching six-wheel rovers on the Martian surface, taking pictures and taking selfies.
Matthew Shindell, from the Smithsonian National Museum of Air and Space in Washington, DC, explains that visitors are keen to go to the planetary exhibition in a gallery nestled at the west end of the museum.
Shindell is the curator of the museum's planetary sciences. One of the main features of the gallery is a big showcase containing the versions of all the rovers that NASA sent on Mars, from the small Sojourner rover landed in 1997 to the 2000 Curiosity rover arrived in 2012.
"People love coming to see the rovers and really get an idea of what they look like and how big they are," Shindell said.
Mars has its own mystique, so it may not be surprising that people find the exploration of the red planet attractive. But New Horizons' overview of Pluto, the close encounter between Messenger and Mercury, and Juno's buzzing on Jupiter's poles have all sparked a great public interest.
Linda Elkins-Tanton, from the School of Earth Exploration and Space at Arizona State University, states that the public's appetite for exploration space exceeds the familiar elements of the solar system.
Elkins-Tanton is the scientist responsible for a mission on a strange asteroid called Psyche. It's strange because Psyche is entirely made of metal – the only asteroid of this type in our solar system. While most people have not heard of Psyche, Elkins-Tanton says they are aware of it.
"We are sending this probe to an absolutely uninhabitable place in the sense of the Earth," she says. "Yet, the public engagement that we are already getting two years before launch is profound.It's amazing.People are so stimulated to think of something that they've never had before imagined before and that humans have never visited. "
Elkins-Tanton says she and her team invite the public to explore Psyche with them.
"We are going to send the images that we publish on the Internet so everyone in the world can see them within half an hour of receiving them," she says. "So, everyone will see this crazy world at the same time and we can all scratch their heads together."
This idea of sharing the experience of space missions has been adopted by NASA. Lakdawalla says the public has been able to see the passion and commitment of scientists working on these robotic explorers.
It recalls the day when NASA decided to end the Cassini mission on Saturn by sending the probe into the atmosphere of the planet, where it burned.
"There were cameras on scientists and engineers crying openly at the end of this spacecraft," recalls Lakdawalla. "This really humanized the mission, and so it created that human connection that maybe you had only through astronauts, now you recognize that robotic exploration is a human exploration, humans can not go right now. "