OrbitalHub

(image source)

A super-Jupiter twelve times farther than TESS can usually see, hiding in eight years of archived photometry, pulled out by a physics trick first described in 1936. Gaia23bra b is the first world the Transiting Exoplanet Survey Satellite has ever confirmed by gravitational microlensing, and the result quietly resets how a mission is used.

The signal was small. A background star out near the galactic plane brightened slightly as a foreground orange dwarf drifted across our line of sight. ESA's Gaia spacecraft flagged the brightening in 2023 as a routine gravitational lensing event and dropped it in the alert stream. TESS happened to be staring at the same patch of sky, taking 27-day blocks of images for its usual transit hunt, and captured the same brightening with finer time sampling. Three years later, when Mallory Harris at the University of New Mexico pulled TESS's archive, she noticed a tiny extra wiggle in the light curve, a five-day deviation that Gaia had missed because Gaia was sampling too sparsely. That wiggle was a planet. The paper went on the arXiv on July 1, 2026, and into The Astrophysical Journal Letters the same day (arXiv:2607.01853).

The headline number is just how far away the host system is. TESS was built to chase transits of bright, nearby stars, with its catalog reaching out to about 150 light-years. Gaia23bra b sits at roughly 40,000 light-years, deep in the galactic plane, on the far side of the galaxy's disk from us. Detecting a planet there was not in the original mission plan, and that is what makes the result interesting.

Microlensing is the only planet-finding method that depends on distance rather than proximity to Earth. Transits need repeated passes in front of the star, so TESS sticks to bright nearby targets. Radial velocity gets harder as the star gets fainter. Direct imaging works for young planets still glowing from formation heat, typically hundreds of light-years away.

Microlensing needs only one alignment between a foreground star and a more distant background source. The foreground star's gravity bends the background light into a brief magnifying-glass spike, and any planet orbiting the lens star leaves its own tiny extra spike on top. The alignment never happens twice. As Harris put it, microlensing events "happen once and they're gone."

Less than 5% of the more than 6,000 known exoplanets were discovered this way, according to NASA's Goddard release on the result. Almost all came from ground-based surveys designed specifically for microlensing. The new detection is the first time a survey telescope built for something else has caught a microlensing planet in its own data. TESS has been staring at almost the whole sky on a rolling basis since 2018.

The find points forward to NASA's next flagship astrophysics mission. The Nancy Grace Roman Space Telescope, currently scheduled for an August 30, 2026 launch from Kennedy Space Center, will spend one of its core surveys staring at the galactic bulge, where the stellar density makes microlensing alignments common. Co-author Michael Fausnaugh of Texas Tech, quoted in the NASA release, calls the TESS detection "a bit like a preview of the microlensing NASA's Nancy Grace Roman Space Telescope will do." Roman is projected to find roughly a thousand microlensing planets and a hundred thousand transiting planets across its primary mission.

The trigger was not new TESS data but the existing archive, re-read. Harris and her collaborators at the University of New Mexico, NASA Goddard, Texas Tech, and partner institutions were testing whether TESS's short-cadence light curves contained enough information to recover microlensing signals at all. TESS full-frame images stack into 30-minute cadence products and 200-second cadence for selected targets, dense enough that a small planet-induced anomaly should be visible if you know where to look.

The team went looking in the eight-year archive for events Gaia had flagged as lensing candidates but could not resolve. Gaia23bra was a textbook case: Gaia saw the main brightening, a roughly 30-day event, but the planet's signature sat on top as a small, sharp deviation that Gaia's sparse sampling averaged out.

When Harris pulled TESS data for the same coordinates, the planet's signature was sitting right there. The deviation lasted about five days and produced a measurable second-order change in the light curve that the team modeled as a second lens, in microlensing jargon, a binary-lens event with a planetary-mass companion. The recovered planet, Gaia23bra b, is roughly 1.6 times Jupiter's mass on a Jupiter-like orbit around an orange dwarf star about 80% of the Sun's mass. NASA's release summarizes it as a "super-Jupiter" in a configuration the mission was not designed to find.

Co-author Diana Dragomir, also at the University of New Mexico, told the NASA press operation that "the discovery implies that there are probably other so-called microlensing planets hiding in TESS's data that we hadn't previously thought to look for." Eight years of TESS full-frame images are now a searchable microlensing archive. More detections are likely; the next round of candidates is still being checked.

The Gaia side of the story closes a separate loop. Gaia finished its extended science mission earlier in 2026, ending a roughly 12-year astrometry run that produced the largest three-dimensional map of the Milky Way. Gaia23bra b is one of the last planets Gaia will help find, and shows how Gaia and TESS were complementary: Gaia's wide-field coarse cadence for the alerts, TESS's narrow-field fine cadence for the follow-up.

The underlying physics is the lensing effect Einstein described in general relativity. A massive object between a distant light source and an observer bends the source's light around itself, producing two distorted images that are usually unresolved, so the source just appears brighter. A planet orbiting the lens acts as a smaller secondary mass that produces its own brief spike on top of the main brightening.

The size of that spike depends on the Einstein radius, scaling with the square root of the lens mass times the distances involved. For a stellar-mass lens halfway across the galaxy and a background source further away, the event lasts weeks, and the planet's spike shows up over a few days, which is why the TESS team's detection was a five-day feature on a roughly 30-day main event.

Two practical issues make the detection hard. The first is degeneracy: a single-lens fit can soak up most of the brightening, leaving a small residual that could be a planet, a stellar companion, or noise. Resolving it requires dense photometry where the planet's signature shows up, which is what TESS provides and Gaia did not.

The second issue is the galactic-plane background. Toward the bulge and inner disk, stars are packed so tightly that a TESS pixel, about 21 arcseconds across, often contains multiple stars whose light blends together. The team's workaround was to lean on Gaia's catalog to decompose the TESS photometry into individual stars, then run the microlensing model on the cleaned light curve.

The Roman connection closes this loop. Roman's Wide Field Instrument has roughly 100 times TESS's collecting area and a pixel scale around 0.11 arcseconds versus TESS's 21 arcseconds, which kills the blending problem for the bulge region. Where TESS catches a microlensing planet by lucky overlap, Roman runs a continuous survey of the densest lensing regions. The two missions cover different parts of the galaxy, with TESS's strength being the rest of the galactic plane where stars are sparser.

The discovery does not change what we know about how planets form. The deeper lesson is that eight years of archived TESS photometry is now a real microlensing dataset, and the analysis pipeline used here is reproducible. Expect follow-up papers searching the TESS archive for additional Gaia-flagged lensing events with high-cadence follow-up available.

The next concrete milestone is Roman's launch on August 30, 2026, which moves microlensing from the realm of niche ground-based surveys into a flagship-class statistics engine. Roman's projected yield of around a thousand microlensing planets, paired with TESS's growing archive of opportunistic microlensing detections, will start to give a real census of planets at Jupiter-like orbital distances across the galaxy. Gaia23bra b is the first data point on the TESS side of that census, and it arrived just in time for the Roman team to use as a worked example in their own planning.

Abstract

The blogpost explores relativistic effects on proof-of-work based cryptocurrency protocols. Cryptocurrencies are here to stay and it is quite plausible that future human colonists spread across the solar system and beyond will use a decentralized cryptocurrency as opposed to a fiat currency issued by a central authority. The low transaction fees, the ubiquitous access, not being bound by exchange rates or interest rates, not being controlled by financial institutions who are serving foreign interests -- these are some of the advantages cryptocurrencies will enjoy in the thriving exo-economy.

Motivation

At present, on a cryptocurrency network, the information exchanged by the nodes in the network reaches each node almost instantaneously. The speed at which the TCP/IP packets travel on the network and the fact that the Internet spans only the Earth and the LEO makes this possible. However, once the region the network is spread across will reach certain boundaries, the network size would have negative impact on the network: increasing communication failures due to network delays, more frequent and longer blockchain forks as part of the proof-of-work protocol, network segregation into local sub-networks (let us call them topological forks), just to name a few.

Nullius in verba... as they say. Let's go deeper into details and figure out a feasible solution for a truly interplanetary cryptocurrency.

Cryptocurrency 101

You can think of a cryptocurrency as a digital money ecosystem. Plain and simple. A collection of technologies are part of this ecosystem, all of them the result of years of research in the cryptography and distributed systems fields: a decentralized network of computers, a public transaction ledger -- also known as a blockchain, a protocol that consists of a set of rules for transaction validation, a decentralized consensus mechanism. [ANTO]

A decentralized network of computers ensures the resilience of the network. We can think of both computing power and data storage capabilities. As the computing power is distributed across the network, any disruption can be successfully handled by the network. Transaction data resides on all nodes of the network. This implies that even physical damage done to network nodes will not take out the network.

The blockchain is a public distributed ledger which stores all transactions handled by the network. As the name suggests, the blockchain is a list of data blocks. Each of these blocks contains a set of transactions, as many as can fit in the block, given the maximum size of the block (a characteristic of the network). Transactions contain sender and receiver info, and the amount/asset that is changing ownership, and they are broadcasted and added to blocks by network nodes. Blocks are linked to the previous block in the chain by a cryptographic hash (the hash of the previous block becomes part of the current block). This backward link leads all the way to the first block in the chain, the Genesis block. Each cryptocurrency blockchain has one. The cryptographic hashes have an important role in protecting the blockchain from tampering attempts.

The transaction validation rules enforced by the nodes in the network ensure that the content of each block in the blockchain is valid. By far, the most frequent form of fraud is double spending. The validation process makes sure that the inputs on the transactions exist and that they have not been already spent. The transactions marked as invalid are rejected by the network and do not make it on the blockchain.

The consensus mechanism is designed so that all the nodes in the network can agree on the set of transactions to be included in the current block. It shifts the authority and the credibility required by a central clearing house to a network of nodes. Important to mention here that, inherently, the nodes do not trust each other, and they do not have to because the trust is enforced by the consensus mechanism itself.

The Proof-of-Work

We mentioned above that one of the key innovations that make cryptocurrencies possible is the decentralized consensus mechanism. Currently, the de facto consensus mechanism is the proof-of-work.

The proof-of-work consensus mechanism was proposed by Satoshi Nakamoto in 2008 [NAKA]. In general, a proof-of-work is a piece of data that requires costly and time consuming computational effort, but it is very easy to verify. A very good analogy is one of your semester projects in college... it takes you a whole semester to finalize it, but it takes very little time and effort for your supervisor to evaluate and grade it. Similarly, proof-of-work is used by cryptocurrencies for block generation. For the network to accept the block, nodes must complete a proof-of-work which also guarantees the integrity of the transactions included in the block. The difficulty of the proof-of-work is adjusted by the network so that a new block can be generated every fixed time interval. This fixed time interval is characteristic to every cryptocurrency. Most notably, for Bitcoin this time interval is set to 10 minutes.

Satoshi Nakamoto's solution, emobodied by the proof-of-work algorithm above, achieves consensus on the network without a central trusted authority (hence the name decentralized consensus mechanism).

Enter the Ansible

For the astute reader, it is quite obvious at this point that communication delays between the network nodes have a direct effect on the protocol described above. An important assumption made when the protocol was designed is that these delays are small, and this is why they can be handled by the network when the nodes choose to follow and validate the blocks on the longest blockchain fork. Also, this is the reason why all the nodes in the network can have a say in the network consensus. They all can find a solution for the current block, and they all can be rewarded when they find the solution. The communication delays witnessed by the peripheral nodes will cripple their ability to find solutions and these nodes will not be incentivized to remain in the network. Hence, the segregation of the network effect mentioned earlier.

Unfortunately, given the current technological level of our civilization, we do not have at our disposal a technology that allows us to communicate fast and reliable over the large expanse of space. It would take a hell of a wait time to proces a payment made by a mining corporation in the TRAPPIST-1 system, 12 parsecs within the constellation of Aquarius, to a planetary engineering corporation located in the Sol system... twice 39 years plus the block confirmation time.

Fortunately, the Sci-Fi literature already offers a solution for our problem. For those of you, Sci-Fi nerds like myself, that have already read Rocannon's World [LEGU] and Ender's Game [CARD], the Ansible device must sound very familiar. The ansible is a fictional device capable of faster-than-light communication. To word this differently, an operator of such device can send and receive messages to and from another device over any distance with no delay.

Hence, even if only in the realm of science fiction, we will be able to devise a solution for the problem that the future cryptocurrency enthusiasts, living in the outer space colonies, will eventually face.

The Special Relativity Theorem

Before elaborating more on a required upgrade of the network protocol, we have to discuss the special relativity theorem and its implications on how time and distance are perceived in reference systems.

Albert Einstein was awarded the Nobel Prize in Physics in 1921. He received it for his contributions to the understanding of the photoelectric effect, after publishing a paper on it in 1905. At that point his contributions to the understanding of gravity through his theory of relativity were well known, but the new perspective on gravity offered by Einstein's theory was so controversial that the Nobel Prize Committee members chose to protect their reputation. They decided that it was appropriate to award Einstein the Nobel Prize for "his services to theoretical Physics, and especially for his discovery of the law of the photoelectric effect."

During his research Einstein attempted to reconcile the principle of relativity with the principle of the constancy of the velocity of light. This attempt led Einstein to the discovery of the special relativity theorem. Einstein's Gedankenexperiment (thought experiment) with a test subject travelling by train is very well known in the scientific community. If our human subject is walking towards the front of the train with velocity w with respect to the train, and the train is moving with velocity v with respect to the embankment, then an observer on the embankment will measure as W = v + w the velocity of our subject on the train. If instead of our traveller, we consider a beam of light propagating with velocity c, the velocity measured by the observer on the embarkment would be v + c. However, this violates the principle that the velocity of light is constant in any inertial reference system and equal with c. Einstein found a solution for this problem and thus resolved the incompatibility.

One direct consequence of the special relativity theorem is the Lorentz transformation.

Before the relativity theorem, time in physics had an absolute significance, independent of the state of motion of the reference system. However, every inertial reference system has its own particular time. We always have to be told which inertial reference system the statement of time refers to. If you look at your watch, the time you read is the time as measured in the Earth inertial reference system. By the way, the Earth circles the Sun on an almost circular orbit, which means that any body maintaining a constant position in the Earth reference system should experience some centripetal force. However, this centripetal component is negligible compared to the gravitational pull of the Earth. Hence, engineers use this aproximation when calculating satellite orbits.

Back to our original trail of thoughts... the axiom that lays the foundation for the Lorentz transformation states that every ray of light possesses the velocity of transmission c relative to any inertial reference system. That is the velocity of transmission in vacuo (in a vacuum).

If following Einstein's thought experiments [EINS], the above-mentioned axiom leads to a set of four equations that explain the relation between dimensional and temporal coordinates in two inertial reference systems:

  x' = (x - vt)/sqr(1 - v²/c²)
  y' = y
  z' = z
  t' = (t - x*v/c²)/sqr(1 - v²/c²)

where:

 x, y, z, t coordinates in inertial reference system K,
 x', y', z' , t' coordinates in inertial reference system K',
 v the relative velocity between inertial reference systems;

also, the expression 1//sqr(1 - v²/c²) is known as the Lorentz factor.

The Lorentz transformation equations are a more general case of the Galilean transformation:

  x' = x - vt
  y' = y
  z' = z
  t' = t

which is the basis of the assumptions of the classical mechanics as to the absolute character of both dimensional and temporal coordinates. The above are the result of replacing velocity c with ∞ in the Lorentz transformation equations.

The Lorentz transformation has a few corollaries which have an impact on time dilation, length contraction, relativistic mass, relativistic momentum, and relativistic kinetic energy. The one that concerns us is the time dilation corollary:

 Δt = γΔt'
 
where γ is defined by

 α = 1/γ = sqr(1 - v²/c²)

Assuming a clock at rest in inertial reference system K, and moving with the velocity v in the inertial reference system K', the time Δt' between two ticks as measured in the frame K' is longer than the time Δt between the same ticks as measured in the rest frame of the clock, K.

Relativistic Effects on Proof-of-Work

To better understand the relativistic effects on how relative time is perceived in two inertial reference systems (or Galilean reference systems [EINS]) we have to mention the twin paradox. The twin paradox is a thought experiment that involves two identical twins. One of the twins makes a journey into space onboard a relativistic spaceship, and upon his return to Earth discovers that his twin has aged much more than he did. Depending on how fast the spaceship moves through space and/or how long the journey was, our traveller could return to Earth and realize that several generations have passed meanwhile.

As a direct application of the twin paradox, we have Mazer Rackham, International Fleet Admiral and Ender Wiggin's mentor, as portrayed by Orson Scott Card [CARD]. The fighter pilot who destroyed the Formic Fleet Flagship, killed the Hive Queen, and ended the Second Formic Invasion, Mazer Rackham is sent on a journey on a relativistic spaceship and returns to Earth 100 years later in order to assist the International Fleet. Upon his return he has barely aged a few years.

Similarly, if a subnetwork is moving relative to the rest of the network, the nodes in the subnetwork would experience time dilation as predicted by the special relativity theorem. Hence, they are at a disadvantage compared to the rest of the nodes because they have less time available to find a solution for the proof-of-work problem. In order to make thing square for all the nodes in the network, the difficulty of the problem should be adjusted in each subnetwork using the Lorentz factor: in order to compensate for time dilation, the relativistic nodes should have to solve a simpler problem. Also, their block confirmation time should decrease as well.

One element is missing still... how do ansibles synchronize? What value has the Lorentz factor for each one of them? One simple solution for this problem is having one of the ansibles (let us say the Earth-bound one) broadcasting a beacon every fixed number of seconds. The ansibles interfacing to subnetworks would pick up the broadcast, and by measuring the time interval between the beacons, infer the Lorentz factor. Once the Lorentz factor is determined, the nodes mining on the subnetworks will have their proof-of-work difficulty and the block confirmation time adjusted accordingly.

A more Down-to-Earth Solution for the Problem

We will fork the storyline (pun intended) at Enter the Ansible paragraph, and suggest a more down-to-earth solution for the problem. The peripheral nodes are not to participate in the consensus. Their function would be just to relay messages (a.k.a. payment information) across the network. In our multi-planetary scenario, the nodes working on the proof-of-work would reside on/around the Earth, and the network nodes on Mars or any other region in the Sol system would have to wait 2x (network packets travel time) + (block confirmation time) in order to confirm a payment. However, such a solution would have an Achilles heel very hard to defend... if starting its mining engine, any peripheral node could take over the local network and force a topological fork of the network. For a node, the incentive of staying honest on the current network must be stronger than any reward obtained by cheating.

Concluding remarks

While the blogpost contains some elements of fiction, it accurately describes the cryptocurrency ecosystem, the special relativity theorem, the Lorentz transformation and its corollaries. We would like to thank the readers that went through this exercise with us. Undeniably, cryptocurrencies are disrupting the global economy and they are here to stay. Undeniably, we -- as a species -- will explore and migrate farther than the LEO. History has taught us that decentralization is the key to survival and prosperity. Let us together make the future happen.

References

[ANTO] Antonopoulos, Andreas M., Mastering Bitcoin, Second Edition, O'Reilly Media, Inc., June 2017;
[CARD] Card, Orson Scott, Ender's Game, A Tor Teen Book, 2014;
[EINS] Einstein, Albert, Relativity, The Special and the General Theory, Princeton University Press, 2015;
[LEGU] Le Guin, Ursula K., Rocannon's World, Harper & Row, 1977;
[NAKA] Nakamoto, Satoshi, Bitcoin - A Peer-to-Peer Electronic Cash System, www.bitcoin.org, 2008;