Webb Space Telescope To Provide Details of Two Intriguing “Super-Earths” in the Milky Way

Exoplanet 55 Cancri e and Its Star

Illustration showing what exoplanet 55 Cancri e could look like, based on current understanding of the planet. 55 Cancri e is a rocky planet with a diameter almost twice that of Earth orbiting just 0.015 astronomical units from its Sun-like star. Because of its tight orbit, the planet is extremely hot, with dayside temperatures reaching 4,400 degrees Fahrenheit (about 2,400 degrees Celsius). Spectroscopic observations using Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) will help determine whether or not the planet has an atmosphere, and if so, what that atmosphere is made of. The observations will also help determine whether or not the planet is tidally locked. Credit: NASA, ESA, CSA, Dani Player (STScI)

Astronomers will train Webb’s high-precision spectrographs on two intriguing rocky exoplanets.

Imagine if Earth were much, much closer to the Sun. So close that an entire year would only last a few hours. So close that gravity has locked one hemisphere in permanent searing daylight and the other in eternal darkness. So close that the oceans boil away, rocks begin to melt, and the clouds rain lava.

While nothing like this exists in our own solar system, planets like this—rocky, roughly Earth-sized, extremely hot, and close to their stars—are not uncommon in the Milky Way galaxy.

What are the surfaces and atmospheres of these planets really like? NASA’s James Webb Space Telescope is about to provide some answers.

Exoplanet LHS 3844 b and Its Star

Illustration showing what exoplanet LHS 3844 b could look like, based on current understanding of the planet.
LHS 3844 b is a rocky planet with a diameter 1.3 times that of Earth orbiting 0.006 astronomical units from its cool red dwarf star. The planet is hot, with dayside temperatures calculated to be greater than 1,000 degrees Fahrenheit (greater than about 525 degrees Celsius). Observations of the planet’s thermal emission spectrum using Webb’s Mid-Infrared Instrument (MIRI) will provide more evidence to help determine what the surface is made of. Credit: NASA, ESA, CSA, Dani Player (STScI)

Geology from 50 Light-Years: Webb Gets Ready to Study Rocky Worlds

With its mirror segments beautifully aligned and its scientific instruments undergoing calibration, NASA’s James Webb Space Telescope (Webb) is just weeks away from full operation. Soon after the first observations are revealed this summer, Webb’s in-depth science will begin.

Included in the investigations planned for the first year are studies of two hot exoplanets classified as “super-Earths” for their size and rocky composition: the lava-covered 55 Cancri e and the airless LHS 3844 b. Scientists will train Webb’s high-precision spectrographs on these planets with a view to understanding the geologic diversity of planets across the galaxy, as well as the evolution of rocky planets like Earth.

Super-Hot Super-Earth 55 Cancri e

55 Cancri e orbits less than 1.5 million miles from its Sun-like star (one twenty-fifth of the distance between Mercury and the Sun), completing one circuit in less than 18 hours. With surface temperatures far above the melting point of typical rock-forming minerals, the day side of the planet is thought to be covered in oceans of lava.

Comparison of Exoplanets 55 Cancri e and LHS 3844 b to Earth and Neptune

Illustration comparing rocky exoplanets LHS 3844 b and 55 Cancri e to Earth and Neptune. Both 55 Cancri e and LHS 3844 b are between Earth and Neptune in terms of size and mass, but they are more similar to Earth in terms of composition.
The planets are arranged from left to right in order of increasing radius.
Image of Earth from the Deep Space Climate Observatory: Earth is a warm, rocky planet with a solid surface, water oceans, and a dynamic atmosphere.
Illustration of LHS 3844 b: LHS 3844 b is a hot, rocky exoplanet with a solid, rocky surface. The planet is too hot for oceans to exist and does not appear to have any significant atmosphere.
Illustration of 55 Cancri e: 55 Cancri e is a rocky exoplanet whose dayside temperature is high enough for the surface to be molten. The planet may or may not have an atmosphere.
Image of Neptune from Voyager 2: Neptune is a cold ice giant with a thick, dense atmosphere.
The illustration shows the planets to scale in terms of radius, but not location in space or distance from their stars. While Earth and Neptune orbit the Sun, LHS 3844 b orbits a small, cool red dwarf star about 49 light-years from Earth, and 55 Cancri e orbits a Sun-like star roughly 41 light-years away. Both are extremely close to their stars, completing one orbit in less than a single Earth day.
Credit: NASA, ESA, CSA, Dani Player (STScI)

Planets that orbit this close to their star are assumed to be tidally locked, with one side facing the star at all times. As a result, the hottest spot on the planet should be the one that faces the star most directly, and the amount of heat coming from the day side should not change much over time.

But this doesn’t seem to be the case. Observations of 55 Cancri e from NASA’s Spitzer Space Telescope suggest that the hottest region is offset from the part that faces the star most directly, while the total amount of heat detected from the day side does vary.

Does 55 Cancri e Have a Thick Atmosphere?

One explanation for these observations is that the planet has a dynamic atmosphere that moves heat around. “55 Cancri e could have a thick atmosphere dominated by oxygen or nitrogen,” explained Renyu Hu of NASA’s Jet Propulsion Laboratory in Southern California, who leads a team that will use Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) to capture the thermal emission spectrum of the day side of the planet. “If it has an atmosphere, [Webb] has the sensitivity and wavelength range to detect it and determine what it is made of,” Hu added.

Or Is It Raining Lava in the Evening on 55 Cancri e?

Another intriguing possibility, however, is that 55 Cancri e is not tidally locked. Instead, it may be like Mercury, rotating three times for every two orbits (what’s known as a 3:2 resonance). As a result, the planet would have a day-night cycle.

“That could explain why the hottest part of the planet is shifted,” explained Alexis Brandeker, a researcher from Stockholm University who leads another team studying the planet. “Just like on Earth, it would take time for the surface to heat up. The hottest time of the day would be in the afternoon, not right at noon.”

Thermal Emission Spectrum of Exoplanet LHS 3844 b

Possible thermal emission spectrum of the hot super-Earth exoplanet LHS 3844 b, as measured by Webb’s Mid-Infrared Instrument. A thermal emission spectrum shows the amount of light of different infrared wavelengths (colors) that are emitted by the planet. Researchers use computer models to predict what a planet’s thermal emission spectrum will look like assuming certain conditions, such as whether or not there is an atmosphere and what the surface of the planet is made of.
This particular simulation assumes that LHS 3844 b has no atmosphere and the day side is covered in the dark volcanic rock basalt. (Basalt is the most common volcanic rock in our solar system, making up volcanic islands like Hawaii and most of Earth’s ocean floor, as well as large portions of the surfaces of the Moon and Mars.)
For comparison, the gray line represents a model spectrum of basaltic rock based on laboratory measurements. The pink line is the spectrum of granite, the most common igneous rock found on Earth’s continents. The two types of rock have very different spectra because they are made of different minerals, which absorb and emit different amounts of different wavelengths of light.
After Webb observes the planet, researchers will compare the actual spectrum to model spectra of various rock types like these to figure out what the surface of the planet is made of.
Credit: NASA, ESA, CSA, Dani Player (STScI), Laura Kreidberg (MPI-A), Renyu Hu (NASA-JPL)

Brandeker’s team plans to test this hypothesis using NIRCam to measure the heat emitted from the lit side of 55 Cancri e during four different orbits. If the planet has a 3:2 resonance, they will observe each hemisphere twice and should be able to detect any difference between the hemispheres.

In this scenario, the surface would heat up, melt, and even vaporize during the day, forming a very thin atmosphere that Webb could detect. In the evening, the vapor would cool and condense to form droplets of lava that would rain back to the surface, turning solid again as night falls.

Somewhat Cooler Super-Earth LHS 3844 b

While 55 Cancri e will provide insight into the exotic geology of a world covered in lava, LHS 3844 b affords a unique opportunity to analyze the solid rock on an exoplanet surface.

Like 55 Cancri e, LHS 3844 b orbits extremely close to its star, completing one revolution in 11 hours. However, because its star is relatively small and cool, the planet is not hot enough for the surface to be molten. Additionally, Spitzer observations indicate that the planet is very unlikely to have a substantial atmosphere.

What Is the Surface of LHS 3844 b Made of?

While we won’t be able to image the surface of LHS 3844 b directly with Webb, the lack of an obscuring atmosphere makes it possible to study the surface with spectroscopy.

“It turns out that different types of rock have different spectra,” explained Laura Kreidberg at the Max Planck Institute for Astronomy. “You can see with your eyes that granite is lighter in color than basalt. There are similar differences in the infrared light that rocks give off.”

Kreidberg’s team will use MIRI to capture the thermal emission spectrum of the day side of LHS 3844 b, and then compare it to spectra of known rocks, like basalt and granite, to determine its composition. If the planet is volcanically active, the spectrum could also reveal the presence of trace amounts of volcanic gases.

The importance of these observations goes far beyond just two of the more than 5,000 confirmed exoplanets in the galaxy. “They will give us fantastic new perspectives on Earth-like planets in general, helping us learn what the early Earth might have been like when it was hot like these planets are today,” said Kreidberg.

These observations of 55 Cancri e and LHS 3844 b will be conducted as part of Webb’s Cycle 1 General Observers program. General Observers programs were competitively selected using a dual-anonymous review system, the same system used to allocate time on Hubble.

The James Webb Space Telescope is the world’s premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

3 Comments on "Webb Space Telescope To Provide Details of Two Intriguing “Super-Earths” in the Milky Way"

  1. Babu G. Ranganathan | May 28, 2022 at 8:10 am | Reply

    Babu G. Ranganathan*
    (B.A. Bible/Biology)

    THE CELL could not have evolved. A partially evolved cell would quickly disintegrate under the effects of random forces of the environment, especially without the protection of a complete and fully functioning cell membrane. A partially evolved cell cannot wait millions of years for chance to make it complete and living! In fact, it couldn’t have even reached the partially evolved state.


    Just having the right materials, elements, and conditions do not mean that life can arise by chance.

    Miller, in his famous experiment in 1953 showed that individual amino acids (the building blocks of life) could come into existence by chance. But, it’s not enough just to have amino acids. The various amino acids that make-up life must link together in a precise sequence, just like the letters in a sentence, to form functioning protein molecules. If they’re not in the right sequence the protein molecules won’t work. It has never been shown that various amino acids can bind together into a sequence by chance to form protein molecules. Even the simplest cell is made up of many millions of various protein molecules.

    What many don’t realize is that although oxygen is necessary for life’s processes, the presence of oxygen would prevent life from coming into being. This is because oxygen is destructive unless there are mechanisms already in place to control, direct, and regulate it, such as what we find in already existing forms of life.

    RNA and DNA are made up of molecules (nucleic acids) that must also exist in the right sequence. Furthermore, none of these sequential molecules, proteins, DNA, RNA, can function outside of a complete and living cell and all are mutually dependent on one another. One cannot come into existence without the other.

    Mathematicians have said any event in the universe with odds of 10 to 50th power or greater is impossible! The probability of just a single average size protein molecule arising by chance is 10 to the 65th power. The late great British scientist Sir Frederick Hoyle calculated that the odds of even the simplest cell coming into existence by chance is 10 to the 40,000th power! How large is this? Consider that the total number of atoms in our universe is 10 to the 82nd power.

    The cell could not have evolved. A partially evolved cell would quickly disintegrate under the effects of random forces of the environment, especially without the protection of a complete and fully functioning cell membrane. A partially evolved cell cannot wait millions of years for chance to make it complete and living! In fact, it couldn’t have even reached the partially evolved state.

    Alien beings, even if they do exist, could not have evolved. How could they have survived millions of years while the very biological structures, organs, and systems necessary for their survival were supposedly still evolving? Life, in any form (even a single-celled organism), must be complete, fully integrated, and fully-functioning from the very start to be fit for survival.

    Of course, once there is a complete and living cell then the code and mechanisms exist to direct the formation of more cells. The problem for evolutionists is how did the cell originate when there were no directing code and mechanisms in nature. Natural laws may explain how a cell or airplane works but mere undirected natural laws could not have brought about the existence of either.

    What about synthetic life? Scientists didn’t create life itself. What they’ve done is, by using intelligent design and sophisticated technology, scientists built DNA code from scratch and then they implanted that man-made DNA into an already existing living cell and alter that cell. That’s what synthetic life is.

    Through genetic engineering scientists have been able to produce new forms of life by altering already existing forms of life, but they have never created life from non-living matter. Even if they do, it won’t be by chance but by intelligent design. That doesn’t help the theory of evolution.

    What about natural selection? Natural selection doesn’t create or produce anything. It can only “select” from biological variations that are possible and which have survival value. If a variation occurs that helps a species survive, that survival is called ” natural selection.” It’s a passive process. There’s no conscious selection by nature, and natural selection only operates in nature once there is life and reproduction and not before, so it would not be of assistance to the origin of life.

    Science can’t prove we’re here by chance or design. Neither was observed. Both are positions of faith. The issue is which faith is best supported by science. Let the scientific arguments of both sides be presented.

    Read my popular Internet articles:



    Author of the popular Internet article, TRADITIONAL DOCTRINE OF HELL EVOLVED FROM GREEK ROOTS

    *I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I’ve been privileged to be recognized in the 24th edition of Marquis “Who’s Who in The East” for my writings on religion and science.

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