Area probes that fly near the sun would possibly one day assist to disclose the character of dark matter, a brand new research finds.
Dark matter is the invisible and largely intangible substance that researchers counsel makes up about five-sixths of all matter within the universe. Though dark matter hasn’t been noticed instantly, its existence is hinted at through its gravitational results on the actions of stars and galaxies. What dark matter may be composed of, nonetheless, stays a thriller.
“The invention of dark matter could be one of many largest achievements in human historical past,” research lead writer Yu-Dai Tsai, a physicist on the College of California, Irvine, instructed Area.com.
Associated: Could the Large Hadron Collider discover dark matter?
Within the new research, the analysis workforce proposed a brand new approach to uncover the character of dark matter, utilizing probably the most exact timepieces ever made: atomic clocks. Whereas grandfather clocks hold time by monitoring swinging pendulums, atomic clocks monitor the quantum vibrations of atoms. At present, one of the best atomic clock is so exact, it’ll primarily lose simply one second every 300 billion years.
Atomic clocks are despatched into space usually. As an illustration, GPS satellites depend on atomic clocks to broadcast exactly timed messages that every GPS receiver makes use of to assist pinpoint its location.
Within the new research, the physicists counsel launching a mission, tentatively dubbed SpaceQ, to an orbit close to the sun. Lately, NASA despatched the Parker Solar Probe nearer to the sun than another spacecraft had gone earlier than. In 2021, the probe flew throughout the sun’s corona — its ultrahot higher environment — for the primary time, and it continues to circle nearer and nearer to our star.
“There are definitely technical challenges towards realizing a mission just like the one we suggest, not [the] least of which is how one can most successfully defend the delicate quantum sensors from the intense environments one finds close to the sun,” research co-author Joshua Eby, a physicist on the College of Tokyo, instructed Area.com. “However missions just like the Parker Area Probe present that unbelievable issues are attainable, and there appear to be no absolute roadblocks. It can take some R&D [research and development], however this work is hopefully only the start of the method.”
Main candidates for dark matter embrace ghostly ultralight particles. As an illustration, a hypothetical particle often called an axion might have a mass lower than a billionth of an electron’s. Theoretical physicists initially proposed the existence of axions to assist clarify why interactions are seen between some particles however not others.
“If this type of dark matter exists, you possibly can think about that we’re basking in waves of dark matter,” Tsai mentioned.
If dark matter is made from ultralight particles, their insubstantial nature would make them terribly troublesome to detect, explaining why they’ve eluded discovery so far. Nevertheless, as a result of the sun is much heavier than Earth — about 330,000 instances the mass of our planet — it possesses a stronger gravitational pull. In precept, this implies the sun might accumulate considerably extra dark matter to it than Earth does. This better density might make it simpler for probes close to the sun — nearer than Mercury‘s orbit — to detect these ghostly particles.
The Parker Photo voltaic Probe “confirmed that you can ship a satellite very near the sun, sensing new circumstances and making discoveries,” research co-author Marianna Safronova, a physicist on the College of Delaware, mentioned in a statement. “That’s a lot nearer to the sun than what we’re proposing right here.”
In precept, waves of ultralight dark matter particles might set off variations in basic constants of nature, such because the mass of the electron or the power of the electromagnetic power. This, in flip, would change how atomic clocks tick — an impact that is determined by the atoms the clock makes use of. By evaluating how two totally different atomic clocks hold time close to the sun, researchers might discover dark matter. Comparable results additionally could also be seen in future timekeepers that will show much more exact than atomic clocks, reminiscent of so-called nuclear clocks.
“If ultra-light dark matter had been detected in a mission like this, it could be a direct probe of each the density of the dark matter close to the sun and its couplings to atypical matter,” Eby mentioned.
The scientists famous that the SpaceQ mission would require clocks which can be nonetheless underneath growth. As well as, even when it detected dark matter indicators, researchers would wish unbiased experiments to confirm its findings, Tsai famous.
Nevertheless, “in precept, if we will measure dark matter in numerous places, we will map out the density distribution,” Tsai mentioned. “And if the sign will get stronger in the direction of the sun, it could be a compelling smoking-gun signature for discovery.”
The scientists detailed their findings on-line Dec. 5 within the journal Nature Astronomy (opens in new tab).
Comply with us on Twitter @Spacedotcom or on Facebook.
