Since 1995, scientists have found more than 4,000 Earth-like exoplanets. It would surely be your surprise that these planets are outside our solar system. NASA’s Exoplanet Exploration page says the Kepler Space Telescope found most of these.  Astronomers really wanted to find the first “alien Earth.” The Earth-like planets in the Milky Way.  New discoveries show that many small, rocky planets like ours are all over the galaxy.

How Earth-like Exoplanets could Resemble the Earth?

A planet should be small and rocky, like Earth, if it wants to be a good place for life. Besides this, it also needs to be in the right spot around its star, not too hot or too cold. Henceforth, this special spot is sometimes called the “Goldilocks” zone, where it’s just right for liquid water on the planet. As telescopes get better, we’ll also look at other things like what the planet’s air is like and how active its star is.

Earth-like Exoplanets
(Image credit: Nazarii Neshcherenskyi via Getty Images)

Even though finding a planet just like Earth is hard, we’ve found some that are pretty close to being similar to our home.

Earth-like Exoplanets: Let’s Have a Quick Glance!

To answer your quest of how many Earth like planets are there in the universe. We have curated a list of Earth-like exoplanets. So, let’s have a keen and some valuable content!

Gliese 667Cc:

Exoplanets List and Names 2023
An artist’s impression of the surface of Gliese 667Cc. (Image credit: ESO/L. Calçada)

This planet is merely 22 light-years away from us. It’s at least 4.5 times heftier than Earth, as indicated by NASA’s Jet Propulsion Laboratory. This exoplanet whirls around its host star in a mere 28 days, but here’s the twist. The star is a cooler red dwarf. Which is chillier than our sun. This chill factor led scientists to speculate that Gliese 667Cc resides within the habitable zone. Where conditions might allow liquid water to exist.

However, science says that it is one of the Earth-like Exoplanets, but a very noteworthy point arises. Gliese 667Cc was initially detected using the European Southern Observatory’s 3.6-meter telescope in Chile. And it might be positioned too close to the red dwarf. Because the exoplanet is so close to the red dwarf star, it could be in danger of getting heated up by the star’s strong bursts of light called flares.

Kepler-22b:

Kepler-22b is positioned 600 light-years from us. It holds a unique distinction. It clinched the title of being the very first planet discovered by Kepler within its parent star’s habitable zone. However, there’s a catch. It is world dwarfs Earth in size. It is measuring about 2.4 times larger. What remains unclear is the composition of this “super-Earth.” Is it rocky, liquid, or perhaps gaseous? The answer is vague for now!

Besides this, let us tell you an interesting fact too. Kepler-22b’s orbit takes about 290 days, which bears a resemblance to Earth’s 365-day cycle.  Being one the resembled Earth-like Exoplanets, it circles a G-class star, akin to our sun, but with a twist. This star is smaller and cooler compared to our familiar sun.

Habitable Exoplanets
Artist’s illustration of Kepler-69c. (Image credit: NASA Ames/JPL-Caltech/T. Pyle)

This Earth like exoplanet Kepler-22b is located a vast 2,700 light-years away. It presents another enigma. This world succeed the Earth’s size by about 70 percent. However, the makeup of Kepler-69c remains a mystery, much like its counterparts.

Taking a closer look, Kepler-69c takes a brisk 242-day journey to complete one orbit around its star. This places it in a position in its own solar system similar to where Venus resides in ours. An interesting distinction arises in the form of Kepler-69c’s host star. It’s roughly 80 percent as radiant as our sun. Which if giving us a hit of the possibility that this planet snuggles within its star’s habitable realm.

Kepler-62f:

NASA has discovered a planet called Kepler-62f. It is about 40% bigger than Earth. This planet goes around a star that’s cooler than our Sun. It takes 267 days for Kepler-62f to complete one orbit. And it’s in the part of space that’s just right for living things.

Here’s an interesting fact: Even though Kepler-62f is closer to its star than Earth is to the Sun, the star doesn’t give off as much light.

Kepler-62f is quite far away, around 1,200 light-years from us. It’s a good size for a planet, which means it might be rocky like Earth. And there’s a chance it could have oceans, which is pretty exciting!

TRAPPIST -1e:

This planet is just a little bit bigger than Earth, not more than 10% larger. Among the group of planets, one called TRAPPIST-1e stands out. Scientists think it could be a good place for life we know. It’s in the habitable zone, but it’s on the outer edge.

Earth-like Exoplanets
This illustration shows the TRAPPIST exoplanets nearest their star. (Image credit: NASA/JPL-Caltech)

Then there’s Kepler-186f. It’s different from Earth because it only gets a third of the energy from its star. This planet is about 500 light-years away from us.

Around a star called TRAPPIST-1, there’s an amazing group of planets. They’re the most Earth-sized planets we’ve found in a zone where conditions might be right for life. That is the reason science says it is one the most acceptable Earth-like exoplanets. There are seven of them altogether, and one of these special planets is called TRAPPIST-1e. It’s the most likely place where life could exist, at least as we know it.

Kepler-186f’s:

Habitable Planets
A planet the size of Kepler-186f is likely to be rocky. (Image credit: NASA Ames/JPL-Caltech/T. Pyle)

Kepler-186f’s star is a red dwarf, which makes it not exactly like Earth. This interesting planet is signaling to us from a faraway distance of around 500 light-years.

What exoplanet is most like Earth?

Kepler-452b, occasionally dubbed as Earth 2.0 or Earth’s Cousin due to its features, is a captivating super-Earth exoplanet. This world gracefully revolves along the inner boundaries of its star Kepler-452’s habitable zone. Notably, Kepler-452b stands as the sole inhabitant of this planetary system. Its other identity, Kepler Object of Interest KOI-7016.01, holds relevance in the astronomical community.

Habitable zone
An artist’s impression compares Kepler 452b with Earth. (Image credit: NASA/Ames/JPL-Caltech/T. Pyle)

Are there any Earth-like exoplanets?

  • Gliese 667Cc.
  • Kepler-22b.
  • Kepler-69c.
  • Kepler-62f.
  • Kepler-186f.
  • Kepler-442b.
  • Kepler-452b.
  • Kepler-1649c.

What is the closest Earth-like exoplanets?

Merely four light-years distant, Proxima Centauri b holds the esteemed title of being our nearest known exoplanetary neighbor. This intriguing celestial body, known as Proxima b, falls within the super Earth category. It gracefully orbits an M-type star. Weighing in at 1.27 times the mass of Earth, this exoplanet completes its orbit around its star in a mere 11.2 days. Positioned at a distance of 0.0485 astronomical units (AU) from its star, Proxima b entered our awareness with its discovery announcement in 2016.

Have we found another planet like Earth?

NASA researchers have just unveiled an exciting discovery. They’ve come across a planet known as TOI 700 e, which boasts a striking resemblance to Earth. The size and shape of TOI 700 e are nearly identical to our own planet, standing at about 95%. Adding to its intrigue, this newfound world features a solid, rocky exterior. What’s even more captivating is that TOI 700 e occupies a special place within its star’s habitable zone, suggesting the tantalizing possibility of water existing on its surface.

Does Kepler-452b have humans?

The presence of life on Kepler-452b remains uncertain, yet intriguing parallels with Earth emerge. Notably, this exoplanet shares a resemblance with our own world. Kepler-452b, for instance, takes approximately 385 Earth days to gracefully complete its orbit around its star. This duration is just slightly extended compared to the span of one Earth year.

What habitable planet is 4 light years?

Astronomers have caused quite a stir with their latest revelations about Proxima b—an exoplanet deemed “highly habitable.” This distant world is merely a short 4.2 light-year hop away from Earth. The scientific community is abuzz with excitement as they contemplate the potential significance of this discovery. It’s believed that Proxima b might be making significant impact across the cosmos, as it possesses conditions that could support vast oceans of liquid water.

What other planet can we live on?

In the most recent turn of events, a groundbreaking discovery unfolded. Merely last year, scientists revealed the existence of yet another Earth-like planet. This remarkable world orbits around Proxima Centauri, one of our nearest neighboring stars. Remarkably, this planet stands as the prime contender in our search for a suitable habitat for human life.

Is there a planet like Earth in the habitable zone?

Using information from NASA’s Transiting Exoplanet Survey Satellite, scientists have done something incredible. They’ve found a planet called TOI 700 e that’s about the same size as Earth. It’s in a good spot around its star, where it’s not too hot or too cold. This special area is where water on a planet could be liquid.

How the Earth-like Exoplanets can Paves the Way in Space Science?

Finding star systems with planets like Earth in this special area is really important. It helps scientists learn more about how our own solar system began.

In the past, many of these planets might have lost their water when they were young. But in 2018, a study suggested that some of these planets could have even more water than Earth’s oceans.

Scientists define the hopeful habitable zone as the area around a star where there could have been liquid water at some point in the past. It goes beyond the more conservative habitable zone, where scientists think liquid water might have been possible for a long time.

It is quite surprising that this week NASA’s Curiosity Mars rover made a discovery. They detected the highest recorded amount of mars methane when they started the mission to Mars. If we look at the keen details. Then it is approximately 21 parts per billion units by volume (ppbv). To ease your thinking what ppbv is, then if you take a volume of air on Mars. It is one billionth of that volume is compose of methane.

Who was Responsible for Sample Analysis at Mars Methane?

The rover’s Sample Analysis at Mars (SAM) tunable laser spectrometer is responsible for this finding. This is very interesting because microbial life is a significant methane source on Earth. And methane can also be produce through interactions between rocks and water.

The Role of Curiosity’s Mars Methane Mystery:

Curiosity lacks instruments that can definitively identify the origin of the methane. Or they will determine whether it originates from a local source within Gale Crater or somewhere else on the planet.

Paul Mahaffy is SAM Principal Investigator of NASA in Maryland. He said:

“With our current measurements, we have no way of telling if the methane source is biology or geology, or even ancient or modern.”

Why the Knowledge of Curiosity’s Team is Very Limited in Mars Methane Mission?

The Curiosity team has identified methane on many occasions during the mission. Earlier studies gives us a knowledge that how the background levels of this gas is changes with time. Additionally, they’ve also observed sudden spikes in Mars methane concentrations. However, scientists believes that the understanding of team during these brief details are not full fledge. And the reasons for the changes of methane gas from seasonal patterns is not enough too.

To gain more detail about potential plumes, the SAM team conduct an experiment for this weekend. The scientists at Curiosity require time to analyze these clues and carry out some methane-related observations. They also need the opportunity to collaborate with other scientific teams. Which includes those affiliated with the European Space Agency’s Trace Gas Orbiter too.

How the Trace Gas Orbiter of ESA Help out in Mars Methane Research?

The ESA’ orbiter has been in its scientific orbit for just over a year. During which it hasn’t detected any methane. So, when scientists combined data from both surface-based and orbital observations. It might assist researchers in pinpointing methane sources on the planet. And, this approach will pave the way on how long the gas persists in Mars’ atmosphere. Such an approach could further assists in the differences. This will provide a keen difference between the methane observations made by the Trace Gas Orbiter and Curiosity.

What are the Findings of Tunable Laser Spectrometer:

On average, the TLS (tunable laser spectrometer) has recorded Mars methane levels. And it has observed that less than half a part per billion by volume within Gale Crater. That is why, to put this into a perspective. It is like having roughly a pinch of salt spread out in an Olympic-size swimming pool. Besides these measurements, there have been perplexing instances of methane spikes reaching as high as 20 parts per billion by volume too.

Webster, who’s based at NASA’s Jet Propulsion Laboratory in Southern California. He said:

“But when the European team announced that it saw no methane, I was definitely shocked.”

Let’s Know More About ESA’ TLS:

The European orbiter was specifically crafted to serve as the benchmark for methane and other methane gas measurements across the entire planet. That is why, Curiosity’s TLS is remarkably accurate. To the extent that it will be employed to provide early warnings for fires on the International Space Station and to monitor oxygen levels within astronaut suits.

Moreover, Mars methane has been authorized for utilization in power plants, along oil pipelines. And within fighter aircraft, offering pilots the capability to track oxygen and carbon dioxide levels in their breathing apparatus.

These findings from the European orbiter took Webster and the SAM team by surprise, prompting them to swiftly embark on an examination of the TLS measurements on Mars.

Curiosity rover
NASA’s Curiosity rover took this selfie on June 15, 2018, which was the 2082nd Martian day, or sol, of the rover’s mission. A dust storm had reduced sunlight and visibility at the rover’s location, which was at the “Duluth” drill site just north of the Vera Rubin Ridge. A small drill hole is visible on the large boulder to the left of the rover. Self-portraits are created using images taken by Curiosity’s Mars Hands Lens Imager.
Credits: NASA/JPL-Caltech/MSSS.

Some experts suggested that the rover itself was releasing the gas. For instance, Webster said:

“So we looked at correlations with the pointing of the rover, the ground, the crushing of rocks, the wheel degradation—you name it. I cannot overstate the effort the team has put into looking at every little detail to make sure those measurements are correct, and they are.”

Webster and his team reported their results today in the Astronomy & Astrophysics journal.

What are the Findings of John E. Moores from York University in Toronto?

As the SAM team worked to confirm its methane detections. Another member of Curiosity’s science team, planetary scientist John E. Moores from York University in Toronto. He published an intriguing prediction in 2019.

“I took what some of my colleagues are calling a very Canadian view of this, in the sense that I asked the question: ‘What if Curiosity and the Trace Gas Orbiter are both right?”

Why shouldn’t there be methane in Mars atmosphere?

All three locations seem to have been saturate with liquid water in the distant past. In fact, the team discovered traces of water vapor within the plumes as well. Methane does not remain the sparse Martian atmosphere. As it is readily breaks down by the intense ultraviolet sunlight that permeates the planet.

Mars Methane
Credit: NASA/JPL-Caltech

Did curiosity find methane on Mars?

This week, NASA’s Curiosity Mars rover made a surprising discovery: it detected the highest recorded amount of methane since the mission began — approximately 21 parts per billion units by volume (ppbv). To put it simply, if you take a volume of air on Mars. It is one billionth of that volume of the methane.

Why is methane an important thing to explore if we are considering colonizing mars?

Additional transformations occurring within the Martian atmosphere could be a significant factor contributing to the noted seasonal fluctuations. Regardless of whether these transformations are link to geological or biological processes, the shifts in methane concentrations that have been documented suggest that Mars might still exhibit ongoing activity in the present day.

What the Scientists have been yet observed information related to Mars Methane?

Although this study indicates that methane levels goes ups, and downs over the day on the surface of Gale Crater. The larger puzzle regarding methane distribution across Mars is still a mystery. Methane is a stable molecule that should persist on Mars for around 300 years before solar radiation. However, scientists believe that something is causing methane to emits in under 300 years.

Experiments are currently underway to investigate important information. This will entails that whether minimal electric discharges triggered by dust on Mars could pull apart methane.

Webster said:

“We need to determine whether there’s a faster destruction mechanism than normal to fully reconcile the data sets from the rover and the orbiter”

If you are wondering is there any need of space agriculture, then your concern is right. Astronauts, and employees who work in space can’t simply make a quick visit to the grocery store, if they need any good range of healthy meal choices. That is why there is a need to have the farming concept in space too.

 And this is done to have a fresh, and healthy diet during long space missions. Astronauts must have nutrient-packed food available. Till today, they bring the majority of their needed food from Earth. And as its very common that space missions got prolonged. That is why it has become important for the researchers to cultivate plants. This cultivation will serve to enhance their diet and provides a good atmosphere like home to them too.

Today, we will highlight some of the major projects by NASA & ESA when it comes to the space agriculture research.

What Backgrounded Study has been Provided by SpaceX?

As SpaceX’s 25th cargo resupply mission for NASA (SpX-25) is all ready towards the International Space Station. It will be transporting an important space agricultural and its biology study. Furthermore, this investigation also holds the potential to revolutionize the methods that we use to cultivate and sustain crops. That is why both in the space environment and on our home planet Earth will have a better point of view about agriculture.

How SpaceX has Conduct a Study on Space Agriculture?

This experiment is known as Dynamics of Microbiomes in Space” (DynaMoS). And it centers around the investigation of small organisms that we don’t know. Moreover, the initial indications of life on Earth trace back more than three billion years.

These microorganisms that is also known as microbe. They will eventually paved the way for all the life forms thriving on our planet today. With the passage of time, these microbes have evolved to effectively to the  available resources. And soil stands out as one of the most common, and opted ecosystems that has diverse microbial communities.

Microbes that stays in the soil plays a crucial role in the carbon cycle. And that is why the circulation of other essential nutrients, which in turn supports the growth of plants. Which is an important factor for the quality sustain of all life.

The DynaMoS project has a aim to dissect the impact of microgravity in space agriculture. And other variables on the metabolic plays important role among communities of soil microorganisms. This study will particularly highlight the soil microorganism groups which is known as  chitin. It is basically a carbon polymer that ranks as the second most prevalent on our planet.

Results from the Dynamics of Microbiomes in Space (DynaMoS) investigation will compare soil samples full of microbes flown aboard the International Space Station and ground control samples at the Kennedy Space Center (KSC).

How Space Agriculture Pave a Way in Science Inventions & Discoveries?

As we all know that consistent efforts plays an important role in the plant growth. And they holds a good significant in space exploration. This is why paving into the microorganism communities that are found within soil takes on fundamental role in our many space explorations.

What is BPS & How it Contributes to Space Agriculture?

NASA’s Biological and Physical Sciences Division takes the lead in driving scientific revelations. And it further facilitates the science exploration. They do it by harnessing space environments for conducting studies that is not possible on Earth.

We all know that investigating biological and physical phenomena within extreme conditions provides researchers with so much knowledge.  With the means to push forward the important scientific insights necessary for extending our reach and duration in space missions.  Aside from this, the future space agriculture’s research yield valuable insights that have practical applications here on Earth.

Dynamics of Microbiomes in Space
Four bags containing 13 tubes each, like this one filled with soil, will fly to the International Space Station as part of the Dynamics of Microbiomes in Space (DynaMoS) investigation.

Important Words by a Scientist of BPS (Biological and Physical Sciences)

Dr. Mamta Patel Nagaraja. Who is a deputy program scientist for space biology for NASA’s Biological and Physical Sciences (BPS) division. He said:

“Farmers on Earth face challenges with weather changes, balancing carbon levels in soil, and other unpredictable forces, but growing crops in space is a whole different playing field.

One factor that is key is understanding how soil microbes perform and function in microgravity since they heavily affect the carbon and nutrient levels. Understanding the behavior of these microbes in spaceflight has the potential to improve agricultural production for long duration space travel. Which includes to other planets, and of course, farming right here on Earth.”

What is APH & How it Contributes to Space Agriculture?

The Advanced Plant Habitat (APH) also serves as a growth chamber into the station which helps in the plant research. This system has LED lights and a micro clay substrate. That is couple with control release fertilizer. It effectively provide water, nutrients, and oxygen to the plant roots.

However, what sets APH apart is its enclosed and automated design. Which is equipped with cameras and over 180 sensors. They maintain constant communication with a ground-based team stationed at Kennedy.

Space Agriculture
John “JC” Carver, a payload integration engineer with Kennedy’s Test and Operations Support Contract, opens the door to the growth chamber of the Advanced Plant Habitat Flight Unit No. 1 for a test harvest of half of the Arabidopsis thaliana plants growing within.
Credits: NASA/Leif Heimbold

Furthermore, it demands less day-to-day attention from the crew. Automation handles aspects such as water recovery and distribution, atmospheric composition, moisture levels, and temperature regulation. APH features an expanded palette of LED light colors compared to Veggie, including red, green, blue, white, far red, and even infrared. Which further benefits the nighttime imaging capabilities.

What is BRIC LED Lights?

The Biological Research in Canisters (BRIC) serves as a facility that help out in investigating the impact of space conditions on tiny organisms. Which can be cultivate in petri dishes. These organisms encompass entities like yeast and microbes. The latest iteration, known as BRIC-LED, has introduced light-emitting diodes (LEDs) to cater to biological specimens such as plants, mosses, algae, and cyanobacteria that rely on light to produce their sustenance.

Currently, BRIC-LED is undergoing tests to validate its hardware. Scientists are diligently ensuring that the LEDs remain within suitable temperature ranges for the plants while also conducting various system checks. In the near future, researchers like Dr. Simon Gilroy from the University of Wisconsin-Madison will utilize this facility to carry out their studies.

When did NASA start growing plants in space?

The timeline of these space-based projects of space agriculture is as follows:

  • Advanced Plant Habitat. It commenced its journey aboard the ISS in April 2017.
  • Bion Satellites. That stary back in 1973.
  • Biomass Production System. Which embarked on its mission in April 2002 aboard the ISS.
  • Vegetable Production System (Veggie). And it took off in May 2014, finding its place aboard the ISS.

How does NASA help agriculture?

NASA Acres collaborates with various stakeholders within the agricultural domain to create data and tools derived from Earth observatories. These resources are aims at enhancing production levels. While protecting the land, water, the atmosphere, and human well-being.

What food did NASA grow in space?

NASA has achieved successful cultivation of plants. That includes lettuce and radishes, and has examined their reactions to the space environment in space agriculture research. This has a comprehensive analysis ranging from gene expression to even assessing the spiciness of the plants. NASA’s Plant Habitat-04 experiment further builds upon prior endeavors, extending to the growth of peppers within the confines of the Advanced Plant Habitat (APH).

Farming Projects by NASA
The first growth test of crops in the Advanced Plant Habitat aboard the International Space Station yielded great results. Arabidopsis seeds – small flowering plants related to cabbage and mustard – grew for about six weeks, and dwarf wheat for five weeks.
Credits: NASA

What is the NASA Veggie program?

The Vegetable Production System (Veggie) stands as a plant growth setup developed and employed by NASA within the context of outer space conditions. Veggie holds a dual purpose: to furnish astronauts with a self-sustaining and lasting food source, while also offering a platform for leisure and relaxation through therapeutic gardening activities.

Space Agriculture
Zinnia plants from the Veggie ground control system are being harvested in the Flight Equipment Development Laboratory in the Space Station Processing Facility at Kennedy. A similar zinnia harvest was conducted by astronaut Scott Kelly on the International Space Station. Credits: NASA/Bill White

What is the Role of ESA in Space Agriculture?

On January 25, 2023, the European Space Agency (ESA) has a collaboration with the German Aerospace Centre (DLR) and the German Federal Office for Agriculture and Food (BLE). They held an event that united the research of space agriculture in space exploration and agri-food sectors. The goal was to collaboratively address common challenges and lay out a shared trajectory for progress.