Unveiling the Cosmos: How Much Space Have We Really Explored?

Scott Daly

astronaut in spacesuit floating in space

Space, the final frontier, has always captivated human curiosity. We’ve sent spacecraft to the moon, rovers to Mars, and probes to the farthest reaches of our solar system. But how much of the vast cosmos have we actually explored?

The scale of the universe is mind-boggling. It’s so vast, it’s hard to comprehend just how little we’ve uncovered. Despite our best efforts, we’ve only just scratched the surface. The quest for knowledge continues, pushing the boundaries of our understanding.

In the grand scheme of things, we’re still cosmic infants, taking our first tentative steps into the unknown. The journey of space exploration is a long one, and we’ve only just begun. Stay tuned as we delve deeper into just how much of space we’ve explored.

What Percentage Of Space Have We Explored?

It’s difficult to determine how much of space we’ve explored due to various reasons. These include the vastness of space, limited technological capabilities, and the fact that we have only sent spacecraft to a small fraction of the universe.

The Vastness of SpaceSpace is unimaginably immense. Even our own galaxy, the Milky Way, contains hundreds of billions of stars and planets. The universe contains countless galaxies like our own, stretching for billions of light-years.
Exploration vs. ObservationWe can observe distant celestial objects using telescopes, but physical exploration is extremely limited to our own solar system with some probes venturing slightly beyond.
“Explored” DefinitionDoes “explored” mean sending a robot/probe, receiving signals from distant objects, or physically landing with humans? Each category yields a vastly different “percentage”.

What we CAN say:

  • Physical Exploration: We’ve sent probes to all planets in our solar system, landed on some moons, and a few objects ventured slightly into interstellar space (Voyager probes)
  • Telescopic Observation: We can see billions of light-years into the universe, detecting the faint light from distant galaxies. However, this is observation, not direct exploration.

Bottom Line: A meaningful percentage is hard to pin down. The majority of the universe remains unvisited and vastly out of reach with current technology. Our exploration efforts remain a tiny speck compared to the true scale of the cosmos.

Key Takeaways

  • Our exploration of space started scarcely 70 years ago, beginning with Yuri Gagarin’s pioneering orbit around the Earth. Despite significant progress, we remain at the early stages of understanding the universe.
  • Space missions shifted over time from brief trips to enduring stays in space, building space stations like Russia’s Mir and the International Space Station (ISS), to study the effects of microgravity on humans.
  • Beyond human missions, robotic explorations, such as the Mars Rovers and Voyager probes, have extended our reach even further into space and yielded essential insights about our universe.
  • The Voyager Probes are our farthest reaching spacecraft to date, having crossed into the realm of interstellar space and providing us with valuable data about the universe.
  • Key future developments in space exploration include the launch of the James Webb Space Telescope, increased focus on moon missions, and ongoing plans for manned Mars missions.
  • Despite considerable advances, we’ve explored only a fraction of our universe. The future promises many more discoveries as technology advances refine our capabilities to explore beyond known frontiers.

Human Missions to Space

Space exploration has undoubtedly fascinated humanity for millennia. Yet, it’s only in the last 70 years or so that we’ve managed to begin understanding the vast cosmos in tangible ways. The foray into the great expanse began when Yuri Gagarin orbited the Earth in 1961—a historic validation of human potential.

Human missions to space have been pivotal in shaping our knowledge and perspectives on the universe. Marked by momentous strides, these missions have taken us from the closest quarters of Earth to the moon’s barren landscape.

The spotlight often falls on the Apollo Program, where NASA shook the world by landing the first humans on the moon. Neil Armstrong’s ‘small step’ in 1969 became a giant leap for human accomplishments in space.

But it’s not all about the moon. Over time, the focus of space missions shifted, with an increased emphasis on living longer in space. Scientists wanted to understand the impact of long-duration microgravity on the human body. The building of space stations, including Russia’s Mir and the International Space Station (ISS), has been paramount in such investigations.

Here’s a brief overview of the duration spent by humans in space as of December 31, 2020:

SpacecraftNumber of MissionsCumulative Days in Space
Apollo Program1780
Space Shuttle1351240
ISSOngoing20 years and counting

Moreover, our reach has extended to Mars—courtesy of robotic missions like Mars Rovers. Although not humans per se, these missions still constitute extensions of ourselves, aiding in our understanding and exploration of the red planet.

Notably, space agencies aren’t the only players anymore. The emergence of private entities, like SpaceX, has given new impetus to space exploration. The company’s successful launch of two NASA astronauts to the ISS in May 2020 symbolizes the shift.

As our presence expands further into the cosmos, the frontiers of our knowledge push outwards too. No doubt, the ceaseless pursuit of discovery will keep humanity reaching for the stars. Yet, we should remind ourselves that we’re merely dipping our toes in the gigantic cosmic ocean.

Robotic Exploration Beyond Mars

Exactly how far has humanity reached into the deep cosmic abyss? With earlier paragraphs bringing up Mars, there’s an obvious question: What’s beyond?

Various robotic missions have ventured past Mars, furthering our understanding of the blossoming cosmic environment. The Voyager missions are key examples. Launched in 1977, NASA’s Voyager 1 and 2 have become some of the distance champions of space exploration.

Voyager 2, in particular, is the only spacecraft to have visited Neptune and Uranus. As of 2021, it’s been surviving in the harsh conditions of space for an impressive 44 years, and it’s almost 18 billion kilometers away from Earth. Here’s a small summary of the Voyagers’ milestones:

MissionDistance from Earth (billion km)Years since launch
Voyager 122.544
Voyager 21844

But they’re not the only explorers. In 2006, the New Horizons probe was launched, targeting the icy-world of Pluto. By 2015, it had accomplished its mission, providing the first-ever close-up images of Pluto and its moons.

While these missions have dramatically expanded our grasp of the solar system, efforts aren’t slowing down. Excitingly, NASA’s Pioneer 10 and 11, along with the Voyagers, are making their way toward the interstellar environment.

The era of robotic exploration goes further than just our planetary neighbors. Satellites are venturing into interstellar space, pushing the boundaries of our knowledge and capabilities. It truly feels like we’re riding the crest of a wave that could carry us into a deeper understanding of our incredible universe.

In the relentless pursuit of discovery, humanity’s reach into the cosmos continues to extend, catalyzed by these robotic explorers. As we uncover more secrets of our vast cosmic garden, one can only wonder: how much more is out there waiting to be discovered?

Voyager Probes’ Journey to Interstellar Space

In the realm of space exploration, few missions have been as impactful as Voyager 1 and Voyager 2. Launched in 1977 by NASA, these robotic emissaries undertook an ambitious project, delivering significant insights about our vast universe.

Voyager 1, paving the way for interstellar exploration, became the first man-made object to cross the heliopause, reaching interstellar space in 2012. This was a historic moment, marking humanity’s first-step into the uncharted territory beyond our solar system. Voyager 2, following closely, reached this milestone in 2018.

The journey hasn’t been easy. The Voyager probes faced challenges like distance, extreme cold, and harmful radiation. Despite these hurdles, they have proven resilient, their power systems expected to keep them functional until 2025, nearly half a century after their launch.

Collectively, the probes have expanded our knowledge of the outer solar system. They revealed active volcanoes on Jupiter’s moon Io, the intricacies of Saturn’s rings, and the bluish hue of Neptune’s atmosphere. They’ve returned data about space as they travel further into the unknown, picking up intriguing readings about cosmic rays and plasma waves.

Meanwhile, NASA continues to receive signals from the probes, although these signals are growing fainter. It takes about 21 hours for their signals to reach Earth.

Voyager ProbesLaunch YearArrival at HeliosphereOperational Till
Voyager 1197720122025
Voyager 2197720182025

However, these missions aren’t the finale in our endeavour to explore space. The aptly named New Horizons probe, launched in 2006, is continuing the tradition of exploration set by the Voyagers. The exploration of space, this final frontier, is just beginning. The cosmos awaits, brimming with endless mysteries for us to uncover.

Unveiling the Mysteries of the Universe

When it comes to interstellar exploration, Voyager 1 and Voyager 2 have set a high bar. Launched over four decades ago, these ambitious missions continue to amaze us with their resilience and stunning discoveries. Voyager 1 turned space-faring eyes towards Jupiter’s moon Io, revealing active volcanoes for the first time. But, it’s not just Jupiter’s neighborhood that’s under investigation. Voyager 2 has ventured further afield, studying the intriguing bluish hue of Neptune’s atmosphere.

Space, however, isn’t simply about planets and moons. A vital mission goal is understanding the stuff between them – the interstellar medium. This nebulous area, teeming with cosmic rays and minute dust particles, remains a key piece of our universe’s enduring puzzle.

Historically viewed as empty voids, interstellar spaces have taken on significant importance. They’re far from barren! Now they’re thought to carry clues about galaxy formation and the distribution of matter in the universe. The Voyagers are our invaluable guides in this impressive venture, relaying real-time info despite the severe environments they encounter.

While coping with extreme cold and radiation, these probes are far from retirement. Currently, they’re anticipated to function till about 2025, providing nearly half a century’s worth of unprecedented data. Truth is, they’ve covered only a tiny fragment of space. There’s so much more to uncover about our cosmic backyard.

Out there, waiting, is a cosmos brimming with mysteries. It’s a space-time stage where the rules of physics play out on scales that boggle the mind. Our exploration’s barely begun.

The New Horizons probe, the successor of Voyager, also follows this tradition of discovery. Launched in 2006, it carries an exploratory torch into uncharted territories. Every pinpoint of light observed from Earth hides a wealth of data. From early star formation to black holes’ spiraling dance, there’s much to reveal about our universe.

These tireless voyages into the celestial wilderness expose the realms that’ve always been beyond human sight. Every data fragment adds another piece to the cosmic jigsaw puzzle. Yet, space’s expanse remains largely uncharted. Exploratory milestones like the Voyagers and New Horizons aren’t the end of the trail; they’re merely the start of a long, enlightening journey.

Future of Space Exploration

As we strive to unveil the cosmic riddles and peel back the layers of the universe, the future of space exploration pulses with promise. Odyssey doesn’t end with the Voyager and New Horizons probes. In fact, they’ve set the groundwork for many thrilling expeditions bound to herald a new epoch in astronomical discovery. So, what’s next?

Scientists and researchers worldwide are heaving efforts into developing innovative technology for upcoming space missions. Among the game-changers in the pipeline is the James Webb Space Telescope (JWST). This technological marvel, set to launch in November 2021, is poised to play a key role in studying previously unexplored territories. It’s bandied about as the successor to Hubble, flaunting hundred times more power. Imagine the cosmic wonders waiting to meet our eyes!

There’s also an upswing in moon missions. For instance, NASA’s Artemis program chiefly aims at landing the “first woman and next man” on the lunar South Pole by 2024. The buzz isn’t only about the historic achievement. Infact, it’s hoped that these moon missions will act as stepping stones for more ambitious plans – a manned mission to Mars.

For the red planet, NASA’s Perseverance Rover is already breaking ground with its Mars samples. But there’s more. Both SpaceX and NASA have outlined plans for manned missions. SpaceX’s Starship, Elon Musk’s ambitious spacecraft, is slated for a Mars landing as early as mid-2020s.

Probes are also being primed for interstellar voyages. Take the Interstellar Probe envisaged by NASA’s Innovative Advanced Concepts (NIAC) program. This novel endeavour could see a spacecraft venture 1,000 Astronomical Units into interstellar space, further than any other.

On the whole, humans have barely scratched the space exterior. Yet, we’re preparing for leaps and bounds in our celestial quest. The voyage of discovery doesn’t end with Voyager or New Horizons. With prospects for expanding our vision, knowledge, and reach, who knows what’s lurking in the depths of otherworldly layers, waiting to be discovered.


We’ve only scratched the surface of space exploration. With the impending launch of the James Webb Space Telescope, we’re on the cusp of unprecedented discoveries. NASA’s Artemis program is set to break new ground with its planned lunar landing, while initiatives like the Perseverance Rover, SpaceX’s Starship, and NASA’s Interstellar Probe are pushing the limits of what’s possible. We’re at the beginning of an exciting era of space exploration. As we continue to innovate and push boundaries, we’re not only expanding our knowledge of the cosmos but also venturing into previously uncharted territories. The future of space exploration is bright and full of promise, with much more of the universe waiting to be discovered.

Frequently Asked Questions

What is the James Webb Space Telescope (JWST)?

The JWST is a huge, space-based observatory set to launch in November 2021. It represents a significant development in space exploration, with the potential to facilitate groundbreaking discoveries about the universe.

What is NASA’s Artemis program?

NASA’s Artemis program is a mission aiming to land “the first woman and the next man” on the lunar South Pole by 2024. This mission is seen as a stepping stone for future manned missions to Mars.

What are some notable initiatives in current space exploration?

Notable initiatives in current space exploration include the Perseverance Rover, SpaceX’s Starship, and NASA’s Interstellar Probe. These projects demonstrate ongoing efforts to broaden our understanding of outer space.

What is the future of space exploration?

While humanity has already made significant efforts to explore outer space, the future holds exciting prospects. From ambitious missions like Artemis to technological advancements like JWST, we are set to delve deeper into uncharted cosmic territories and expand our understanding of the universe.