Category: The Conversation

Source: The Conversation – Global Perspectives – By Mireille Rebeiz, Chair of Middle East Studies, Dickinson College

On Sept. 21, 2025, a senior U.S official boasted that an Israeli-Syrian security agreement to resolve months of conflict was “99% complete” and would be announced within two weeks.

Those two weeks have now passed. And the reality on the ground suggests that the two countries are still far from sealing any deal to end the Israeli military incursions into Syrian territory that have occurred since the fall of Syrian President Bashar Assad in December 2024. Just days after the American official gave his prognosis and as negotiations continued, Israel struck several Syrian targets.

Citing negotiation sources, several news outlets reported that the delay in securing a deal was primarily related to Israel’s 11th-hour demand of creating a so-called humanitarian corridor that would link the Israeli-occupied Golan Heights to Sweidah, a city in southern Syria. Israel said the purpose is to protect religious minorities in the Golan Heights and Sweidah.

The hitch, after months of U.S.-mediated talks, reflects Syria’s vulnerability in these negotiations. Seeking to move on after year of war, the current Syrian leadership is eager to snuff out remaining internal violence, secure the borders and return to the United Nations-brokered truce with Israel that had been in place for decades. However, concluding a deal with its militarily superior neighbor risks the further fragmentation of Syria and an entrenched violation of its sovereignty.

Indeed, as an expert on the Middle East, I believe the talks and the potential last-minute snag point to Israel believing it has the upper hand. Meanwhile for Syria, a desire for security can’t mask what it sees as Israel’s expansionist policy in the region, and concerns that it is using things like a proposed humanitarian corridor as a way to achieve recognition of areas only recently under Israeli control.

The fraught history of Syrian-Israeli relations

Following the United Nations’ partition of Palestine in 1947 and the proclamation of the state of Israel in 1948, a coalition of five Arab armies, including Syria, declared war on Israel and lost the ensuing conflict.

As a result, Syria was forced to sign an armistice agreement with Israel on July 20, 1949.

Yet de facto peace never lasted long. The two countries squared off in repeated conflicts in the next 25 years, including the Six-Day War in 1967 that launched Israel’s still-ongoing occupation of Syria’s Golan Heights.

In 1974, the U.N. brokered the Agreement on Disengagement between Israeli and Syrian forces. While not a peace agreement, the pact served to codify a ceasefire and created a buffer zone between the two countries monitored by U.N. observers.

For 50 years, that status quo held uneasily, as subsequent peace efforts failed. The conflict was effectively frozen, punctuated by occasional flare-ups of violence.

Entering the post-Assad era

The fall of Assad and his goverment in December 2024 suddenly injected a new dose of uncertainty into Israel-Syria relations.

As rebel-turned interim President Ahmed al-Sharaa worked to consolidate power and vowed to restore peace and stability for his war-torn country, Israel went on the offensive.

Shortly after the collapse of the Assad government, Israeli Prime Minister Benjamin Netanyahu declared the 1974 Disengagement Agreement “void until order is restored in Syria.” As a result, and in violation of the agreement, Israel occupied the demilitarized zone in the Golan Heights and expanded its control inside Syria. For months, Israel has conducted a campaign of airstrikes across Syria, repeatedly bombing Syrian military positions, including near the presidential palace in Damascus. Israel says it is doing so to stop weapon transfers from Iran and to protect its borders and ensure its security.

At the same time, it has pressed the U.S. to keep Syria weak and divided, in part due to Netanyahu’s and his far-right coalition’s hostility to an Islamist-governed neighbor.

The U.S., at the urging of allies like Saudi Arabia which are close with the Sharaa government, recently lifted sanctions on Syria. For months, officials of the Trump administration have likewise mediated talks and pushed Israel and Syria to conclude an agreement to stop Israel’s seizures and air campaign.

For his part, Sharaa and his negotiators have continually pressed for a halt to Israeli incursions and a return to the 1974 disengagement agreement and the de facto borders it established, describing it as a “necessity.”

Hints of common ground on Hezbollah and Iran

Aside from Syria’s immediate desire and chief priority to end all hostilities on its territory, there are some potential benefits to a new arrangement with Israel from both countries’ perspective.

Before its fall, the Assad government was close to Hezbollah and the Islamic Republic of Iran. Hezbollah, a Lebanese Shia Islamist political party and paramilitary group funded by Iran, supported Assad and played a major role in Syria’s civil war.

Furthermore, under Assad’s government, Syria served as a land bridge between Iran and Lebanon through which Hezbollah fighters transported their military equipment, money and drugs.

Under Sharaa, Syria’s central government is now closely allied to the Arab Gulf countries that have long been Iran’s regional rivals. In strengthening its security, Syria will no longer serve as Hezbollah-Iran meeting point, which will subsequently benefit Israel. For Syria, it will also stabilize the country against Iranian interference.

The risk of Syria’s further fragmentation

The risks of a deal with Israel from Syria’s standpoint, however, are significant.

In defending its incursions into Syria, Israel has pointed to both the security threat it says Syria poses to Israel and also the situation of minority groups in Syria, where sectarian violence has risen against communities like the Christian Orthodox and the Druze.

Israel has floated a number of plans for how it intends to retain a heavy footprint in Syria beyond the occupation of the Golan Heights and the 1974 Agreement of Disengagement.

One option on the table is an extension of the historical buffer zone and splitting Syria into autonomous zones, in which Sweidah province would be a demilitarized buffer zone between Israel and Syria. With the most recent idea of a humanitarian corridor couched in the language of protecting Syrian minorities, Israel could be seeking a wider area under more explicit control.

From the Syrian perspective, all of the above are backdoor ways by Israel to cement post-Assad military actions beyond the scope of the 1974 truce. As such, agreement to a security pact on Israeli terms would mean jeopardizing or shrinking Syria’s sovereignty and territorial integrity.

The Syrian leadership’s challenge going forward

After years of war and fragmentation, most Syrians will take any cessation of hostilities with Israel as a welcome development – but not at any cost. Many Syrians are opposed to further fragmentation of the country. And considering the ongoing killing and displacement of Palestinians in Gaza – described recently by a U.N. body as genocide – and Syria’s historic commitment to pan-Arabism, many Syrians will likely be skeptical if a security deal with Israel means a de facto recognition of the land and sovereignty Israel has acquired since December 2024.

That points to the major dilemma underpinning Sharaa’s position. Syria is in a vulnerable place and is not in position to negotiate from strength, especially as Sharaa tries to open Syria to the Western world, boost its economy and bring back the civil war refugees from neighboring countries. Seeking to consolidate his government’s hold on power and end the presence of a foreign military, Sharaa likely sees a security agreement as in his immediate interest.

While such a pact may bring some stability to Syria and the region, it could also codify Israel’s nearly unchallenged regional power.

Mireille Rebeiz is affiliated with the American Red Cross.

– ref. For war-weary Syria, potential benefits of security pact with Israel comes with big risks – https://theconversation.com/for-war-weary-syria-potential-benefits-of-security-pact-with-israel-comes-with-big-risks-265785

Source: The Conversation – Global Perspectives – By Marika Sosnowski, Senior research fellow, The University of Melbourne

There are jubilant scenes in both Gaza and Israel after both sides in the war have agreed to another ceasefire. If all goes well, this will be only the third ceasefire to be implemented by Israel and Hamas, despite there being numerous other agreements to try to stop the violence.

There is a lot to be happy about here. Most notably, this ceasefire will bring a halt to what has now been established as a genocidal campaign of violence against Palestinians in Gaza, the release of all hostages held by Hamas, and the resumption of aid into Gaza to alleviate the famine conditions there.

However, a lot of unknowns remain. While the terms of the “first phase” of this ceasefire have been rehearsed in previous ceasefires in November 2023 and January 2025, many other terms remain vague. This makes their implementation difficult and likely contested.

After this phase is complete, a lot will depend on domestic Israeli politics and the Trump administration’s willingness to follow through on its guarantor responsibilities.

Immediate positives for both sides

The ceasefire agreement appears to be based on the 20-point plan US President Donald Trump unveiled in the White House alongside Israeli Prime Minister Benjamin Netanyahu on September 29.

What will be implemented in what is being called the “first phase” are the practical, more detailed and immediate terms of the ceasefire.

In the text of the peace plan released to the public, these terms are stipulated in:

• Point 3 – an “immediate” end to the war and Israeli troop withdrawal to an “agreed upon line”.

• Points 4 and 5 – the release of all living and deceased hostages by Hamas in exchange for Palestinian prisoners.

• Point 7 – full aid to flow into the strip, consistent with the January ceasefire agreement terms.

While these steps are positive, they are the bare minimum you would expect both sides to acquiesce to as part of a ceasefire deal.

Over the past two years, Gaza has been virtually demolished by Israel’s military and the population of the strip is starving. There is also great domestic pressure on the Israeli government to bring the hostages home, while Hamas has no cards left to play besides their release.

The text of these particular terms has been drafted in a way that means both Israel and Hamas know what to do and when. This makes it more likely they will abide by the terms.

Both sides also have a vested interest in these terms happening. Further, both parties have taken these exact steps before during the November 2023 and January 2025 Gaza ceasefires.

Given this, I expect these terms will be implemented in the coming days. It is less clear what will happen after that.

What comes next: the great unknown

After the first phase of the ceasefire has been implemented, Hamas will find itself in a situation very similar to ceasefire agreements that occurred during the Syrian civil war that began in 2011 and only recently ended with the downfall of the Assad regime in late 2024. I call these strangle contracts.

These type of ceasefire agreements are not like bargains or contracts negotiated between two equal parties. Instead, they are highly coercive agreements that enable the more powerful party to force the weaker party into agreeing to anything in order for them to survive.

Once the hostages are released, Hamas will go back to having negligible bargaining power of its own. And the group, along with the people of Gaza themselves, will once again be at the mercy of Israeli military might and domestic and international politics.

Other terms of the Trump peace plan relating to Hamas’ demilitarisation (Points 1 and 13), the future governance of Gaza (Points 9 and 13) and Gaza’s redevelopment (Points 2, 10 and 11) are also extremely vague and offer little guidance on what exactly should occur, when or how.

Under such a strangle contract, Hamas will have no leverage after it releases the hostages. This, together with the vague terms of the ceasefire agreement, will offer Israel a great deal of manoeuvrability and political cover.

For example, the Israeli government could claim Hamas is not abiding by the terms of the agreement and then recommence bombardment, curtail aid or further displace the Palestinians in Gaza.

While Point 12 rightly stipulates that “no one will be forced to leave Gaza”, Israel could make conditions there so inhospitable and offer enough incentives to Gazans, they might have little choice other than to leave if they want to survive.

Points 15 and 16 stipulate that the United States (along with Arab and other international partners) will develop a temporary International Stabilisation Force to deploy to Gaza to act as guarantors for the agreement. The Israel Defence Force (IDF) will also withdraw “based on standards, milestones, and timeframes linked to demilitarization”.

But these “standards, milestones and timeframes” have been left unspecified and will be hard for the parties to agree on.

It is also possible Israel could use the vagueness of these terms to its advantage by arguing Hamas has failed to meet certain conditions in order to justify restarting the war.

Knowing it has no leverage after the first phase, Hamas has explicitly said it is expecting the US to fulfil its guarantor role. It is certainly a good sign the US has pledged 200 troops to help support and monitor the ceasefire, but at this stage, Hamas has little choice other than to pray the US’ deeds reflect its words.

While the ceasefire has now been passed by a majority of the Knesset (Israel’s parliament), five far-right ministers voted against the deal. These include Israel’s National Security Minister Itamar Ben-Gvir, who said the ceasefire is akin to “a deal with Adolf Hitler”.

This opposition bloc will no doubt be making more threats – and could potentially act – to bring down Netanyahu’s government after the first phase is implemented.

The problem with ceasefires

The first phase of this ceasefire will offer Hamas and Israel key items – a hostage-prisoner swap, a halt to violence and humanitarian aid.

After that, rather than a bargaining process with trade-offs between negotiating partners operating on a relatively even playing field, without US opprobrium, the ceasefire could easily devolve into an excuse for further Israeli domination of Gaza.

A ceasefire was always going to be a very small step forward in a long road towards peace between Israelis and Palestinians. Without meaningful engagement with Palestinians in their self-determination, we can only hope the future for Gazans will not get any worse.

As a Palestinian leader from Yarmouk camp in Syria told me back in 2018: “If there is a ceasefire, people know the devil is coming.”

Marika Sosnowski does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. The Gaza ceasefire deal could be a ‘strangle contract’, with Israel holding all the cards – https://theconversation.com/the-gaza-ceasefire-deal-could-be-a-strangle-contract-with-israel-holding-all-the-cards-267208

Source: The Conversation – Global Perspectives – By John Hart, Emeritus Faculty, US government and politics specialist, Australian National University

US President Donald Trump’s efforts to deploy the military for law enforcement duties in selected American cities is likely to end up before the US Supreme Court.

If it does, the nine justices will be faced with sorting out a dog’s breakfast of constitutional and statutory laws full of contradictions and ambiguities.

Given the propensity of the current Supreme Court to support and even extend the scope of presidential authority, it could very well rule in Trump’s favour. And this would have far-reaching implications for civil liberties and democracy in the United States.

How did we get to this point, and what does the law actually say about using the National Guard in US cities?

What is Trump attempting to do?

The National Guard is made up of part-time reservists assigned to units in each state. These soldiers are typically called into service by the governors of the states where they serve to respond to disasters or large protests.

In certain circumstances, presidents can also “federalise” National Guard troops, though it rarely happens against a governor’s wishes. Before this year, the last time this happened was in Selma, Alabama, in 1965, to protect civil rights protesters.

In recent months, Trump has attempted to “federalise” the National Guard units belonging to several states and dispatch them to cities (Los Angeles, Memphis, Washington DC, Portland and Chicago) that he claims are out of control.

The troop deployments have been opposed by the Democratic governors in some of these states, then blocked or restricted by temporary restraining orders issued by federal district court judges. (The order in California was subsequently stayed by the US Court of Appeals, pending a further appeal).

There are several issues being contested:

• the conditions under which the National Guard can be mobilised by the federal government
• the degree of collaboration between federal and state governments in issuing orders to the National Guard, and
• the prohibition on the military being used for domestic law enforcement purposes.

Trump’s moves are testing the uncertain boundaries of all these constraints on executive power. But, more significantly, he is also challenging the long-standing American tradition of keeping the military out of domestic politics.

What are the legal issues at play?

The constitutional authority to deploy the National Guard is actually assigned to Congress, not the president. Article 1, Section 8 of the US Constitution gives Congress the power to “provide for calling forth the militia to execute the laws of the Union, suppress insurrections and repel invasions”. Militias have been interpreted to include the National Guard.

However, the Constitution also charges the president with two very significant duties. The first is to “preserve, protect and defend the Constitution of the United States”; the second is to “take care that the laws be faithfully executed”. These two duties can amount to a significant grant of power in times of crisis.

The Trump administration will almost certainly argue he is deploying the National Guard in these US cities to carry out these duties.

There’s a bigger issue for Trump, though. Another law, the Posse Comitatus Act of 1878, makes it illegal for federal troops to engage in civilian law enforcement unless expressly authorised by the Constitution or the law.

Trump is currently acting without this explicit legal authorisation. However,
as the Brennan Center for Justice has recently pointed out, there are 26 different laws that allow for the military to execute the law in specific situations. These exceptions undermine the purpose of the Posse Comitatus Act, making the case for urgent reform of the law.

What about the Insurrection Act?

One of these exceptions is the Insurrection Act of 1807, which gives the president the power to use the military or federalise National Guard troops to put down domestic uprisings. Since the civil rights movement in the 1960s, the act has seldom been used.

Trump said this week he would consider invoking the act to “get around” any court decisions blocking his move to deploy National Guard troops in US cities.

He also claimed the demonstrations against the US Immigration and Customs Enforcement (ICE) building in Portland amounted to a “criminal insurrection”.

Trump then ramped up the rhetoric and the hyperbole even further by calling for the jailing of Illinois Governor JB Pritzker and Chicago Mayor Brandon Johnson for failing to protect ICE agents in that city.

The demonstrations against Trump’s immigration policies in Los Angeles, Portland, and Chicago are nowhere near meeting the definition of insurrection.

But, as the president told the meeting of military generals in Virginia last week, he is keen to push the bounds on using the military in domestic affairs. Or, as he put it, to use these cities as “training grounds” for the armed forces.

If the Supreme Court rules in Trump’s favour on this issue, it would be tantamount to saying the president is the only arbiter on whether a political protest amounts to an insurrection and when it’s necessary to use the military to quell it.

It would also expand the scope for Trump to use the military in other areas of domestic politics.

The president has already deployed the military for border protection, so patrolling universities or even the lines outside polling stations on election day could be next.

John Hart does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Explainer: what powers does Trump actually have to deploy the military to US cities? – https://theconversation.com/explainer-what-powers-does-trump-actually-have-to-deploy-the-military-to-us-cities-267109

Source: The Conversation – Global Perspectives – By Emma Shortis, Adjunct Senior Fellow, School of Global, Urban and Social Studies, RMIT University

[…]we took the freedom of speech away.

We should use some of these dangerous cities as training grounds for our military[…]

They’re poisoning the blood of our country.

Stand back and stand by.

The president has been saying it out loud all along.

During his first administration, in 2019, US President Donald Trump said the Constitution gave him “the right to do whatever I want”. Five years later, the Supreme Court affirmed that view when it ruled the president has quasi-regal powers of immunity for “official acts”.

And then last week at the Marine Corps base in Quantico, Virginia, Trump’s existential threat to American democracy escalated significantly.

Secretary of Defense Pete Hegseth had assembled around 800 of the United States military’s top leaders. Hegseth convened the conference in an attempt to impose an ex-National Guard major’s authority on America’s professional military leadership. He reduced professionalism to physical appearance and fitness standards dressed up as “the warrior ethos” and “lethality”.

His speech was a charge of far-right talking points. Obesity and beards are out. Hyper-masculinisation and misogyny are in.

No more identity months, DEI (Diversity, Equity, Inclusion) offices, dudes in dresses, no more climate change worship, no more division, distraction or gender delusions – we are done with that shit.

Trump commandeered the event. The president’s stream-of-consciousness, campaign-style speech took an even more radical turn.

His disdain for the admirals and generals was clear from the outset. “If you don’t like what I’m saying, you can leave the room – of course, there goes your rank, there goes your future.”

From both Hegseth and Trump, the message was clear. The military leaders in the room – who have all sworn an oath to defend and uphold the Constitution (not, it should be noted, the commander-in-chief) – should consider themselves nothing more than obedient servants of the president.

That in itself would represent a radical shift in civil-military relations.

But Trump, as he always does, took things even further.

He said:

I told Pete [Hegseth] we should use some of these dangerous cities [Washington DC, San Francisco, New York, Los Angeles, Portland] as training grounds for our military.

The president of the United States has decided that the US military, which is now meant to be more focused than ever on “lethality”, should include American cities and the people who live in them in their operational plans.

‘Do whatever the hell you want’

Trump’s main audience for this speech, as usual, was not really the people in the room. It was his MAGA (Make America Great Again) base, a movement that he knows well and plays like a virtuoso. The same base he told to “stand back and stand by” in 2020, just before the January 6 insurrection.

We can bet they are listening. That base knows, instinctively – as does the leadership of the movement – that Trump’s promise of no consequences extends beyond the military. He showed them that when he pardoned those that had tried to overthrow a democratically elected government on his behalf.

This context matters, because Trump, Hegseth and the rest are reshaping not just the military but the entire federal government in their ideological image. Through mass layoffs and recruitment – all laid out in Project 2025 – they are consolidating their power everywhere.

The cities Trump wants the military to use as “training grounds” are the same cities being targeted by violent, oppressive enforcement of the Trump administration’s “mass deportations” policy, led by the Department of Homeland Security and Immigration and Customs Enforcement (ICE).

In practice, those operations include the arbitrary arrest and detention of American citizens and the denial of legal rights and due process. In Chicago, where Trump has just deployed the National Guard, raids have reportedly included pulling children naked from their beds in the middle of the night and separating them from their mothers. Those same agencies using these practices are clashing with protesters in increasingly violent confrontations, and the National Guard is being deployed as reinforcement.

At times during his speech, Trump spoke directly to “border patrol, ICE” saying that if they were spat at or had bricks thrown at their vehicles, “you get out of that car and you can do whatever the hell you want to do”.

The president then went on to immediately compare this to the administration’s attacks on Venezuelan boats in international waters, which the New York City Bar Association has described as “unlawful executions”. As Trump put it: “we take them out.”

ICE is currently engaged in a program of mass recruitment, spending $30 billion to find 10,000 new deportation officers, even going so far as to offer $50,000 bonuses. In July, DHS Secretary Kristi Noem said that recruits were needed because “Together, we must defend the homeland”.

This blood-and-soil style violent nationalism infuses everything the administration is doing, from its recruitment to its firings, from its promises to crackdown on the “radical left” to its suppression of free speech.

The president has repeatedly told the movement behind him, and the military and law enforcement agencies, directly and indirectly, that they are free to impose this radical vision for America violently – without fear of consequence.

An American tragedy

Trump has long mused about using the military against his own people. According to former Defense Secretary Mark Esper, during his first administration, enraged at Black Lives Matter protests, Trump reportedly asked “Can’t you just shoot them, just shoot them in the legs or something?”

On Thursday US time, NBC reported that officials in the White House were having “increasingly serious discussions” about invoking the Insurrection Act, which would allow the President to deploy the military domestically for civilian law enforcement. That process is now, according to an unnamed source, on its way up “an escalatory ladder”.

As has been noted many times, Trump is now surrounded by people who are all-in on his agenda. The guardrails have been dismantled.

What Trump suggested in Quantico would mean the use of unaccountable, unsanctioned force against American citizens delivered by the all-volunteer personnel of the US military.

None of the assembled generals or admirals walked out when he said that.

In the absence of resistance, this transforms the US military into a domestic political tool of the executive and turns American military leaders into the enforcers of presidential political will against the American people themselves.

The meeting at Quantico was a transformation point in the second Trump presidency. It turned the assembled admirals and generals into a de facto enemy of the people.

It transforms the United States into an autocracy and the presidency into a dictatorship.

This is the tragedy of Trump’s America.

Emma Shortis is Director of International and Security Affairs at The Australia Institute, an independent think tank.

– ref. Trump’s tragedy: the US becomes an autocracy and the presidency, a dictatorship – https://theconversation.com/trumps-tragedy-the-us-becomes-an-autocracy-and-the-presidency-a-dictatorship-266675

Source: The Conversation – Global Perspectives – By Michael J. I. Brown, Associate Professor in Astronomy, Monash University

A proposed constellation of satellites has astronomers very worried. Unlike satellites that reflect sunlight and produce light pollution as an unfortunate byproduct, the ones by US startup Reflect Orbital would produce light pollution by design.

The company promises to produce “sunlight on demand” with mirrors that beam sunlight down to Earth so solar farms can operate after sunset.

It plans to start with an 18-metre test satellite named Earendil-1 which the company has applied to launch in 2026. It would eventually be followed by about 4,000 satellites in orbit by 2030, according to the latest reports.

So how bad would the light pollution be? And perhaps more importantly, can Reflect Orbital’s satellites even work as advertised?

Bouncing sunlight

In the same way you can bounce sunlight off a watch face to produce a spot of light, Reflect Orbital’s satellites would use mirrors to beam light onto a patch of Earth.

But the scale involved is vastly different. Reflect Orbital’s satellites would orbit about 625km above the ground, and would eventually have mirrors 54 metres across.

When you bounce light off your watch onto a nearby wall, the spot of light can be very bright. But if you bounce it onto a distant wall, the spot becomes larger – and dimmer.

This is because the Sun is not a point of light, but spans half a degree in angle in the sky. This means that at large distances, a beam of sunlight reflected off a flat mirror spreads out with an angle of half a degree.

What does that mean in practice? Let’s take a satellite reflecting sunlight over a distance of roughly 800km – because a 625km-high satellite won’t always be directly overhead, but beaming the sunlight at an angle. The illuminated patch of ground would be at least 7km across.

Even a curved mirror or a lens can’t focus the sunlight into a tighter spot due to the distance and the half-degree angle of the Sun in the sky.

Would this reflected sunlight be bright or dim? Well, for a single 54 metre satellite it will be 15,000 times fainter than the midday Sun, but this is still far brighter than the full Moon.

The balloon test

Last year, Reflect Orbital’s founder Ben Nowack posted a short video which summarised a test with the “last thing to build before moving into space”. It was a reflector carried on a hot air balloon.

In the test, a flat, square mirror roughly 2.5 metres across directs a beam of light down to solar panels and sensors. In one instance the team measures 516 watts of light per square metre while the balloon is at a distance of 242 metres.

For comparison, the midday Sun produces roughly 1,000 watts per square metre. So 516 watts per square metre is about half of that, which is enough to be useful.

However, let’s scale the balloon test to space. As we noted earlier, if the satellites were 800km from the area of interest, the reflector would need to be 6.5km by 6.5km – 42 square kilometres. It’s not practical to build such a giant reflector, so the balloon test has some limitations.

So what is Reflect Orbital planning to do?

Reflect Orbital’s plan is “simple satellites in the right constellation shining on existing solar farms”. And their goal is only 200 watts per square metre – 20% of the midday Sun.

Can smaller satellites deliver? If a single 54 metre satellite is 15,000 times fainter than the midday Sun, you would need 3,000 of them to achieve 20% of the midday Sun. That’s a lot of satellites to illuminate one region.

Another issue: satellites at a 625km altitude move at 7.5 kilometres per second. So a satellite will be within 1,000km of a given location for no more than 3.5 minutes.

This means 3,000 satellites would give you a few minutes of illumination. To provide even an hour, you’d need thousands more.

Reflect Orbital isn’t lacking ambition. In one interview, Nowack suggested 250,000 satellites in 600km high orbits. That’s more than all the currently catalogued satellites and large pieces of space junk put together.

And yet, that vast constellation would deliver only 20% of the midday Sun to no more than 80 locations at once, based on our calculations above. In practice, even fewer locations would be illuminated due to cloudy weather.

Additionally, given their altitude, the satellites could only deliver illumination to most locations near dusk and dawn, when the mirrors in low Earth orbit would be bathed in sunlight. Aware of this, Reflect Orbital plan for their constellation to encircle Earth above the day-night line in sun-synchronous orbits to keep them continuously in sunlight.

Bright lights

So, are mirrored satellites a practical means to produce affordable solar power at night? Probably not. Could they produce devastating light pollution? Absolutely.

In the early evening it doesn’t take long to spot satellites and space junk – and they’re not deliberately designed to be bright. With Reflect Orbital’s plan, even if just the test satellite works as planned, it will sometimes appear far brighter than the full Moon.

A constellation of such mirrors would be devastating to astronomy and dangerous to astronomers. To anyone looking through a telescope the surface of each mirror could be almost as bright as the surface of the Sun, risking permanent eye damage.

The light pollution will hinder everyone’s ability to see the cosmos and light pollution is known to impact the daily rhythms of animals as well.

Although Reflect Orbital aims to illuminate specific locations, the satellites’ beams would also sweep across Earth when moving from one location to the next. The night sky could be lit up with flashes of light brighter than the Moon.

The company did not reply to The Conversation about these concerns within deadline. However, it told Bloomberg this week it plans to redirect sunlight in ways that are “brief, predictable and targeted”, avoiding observatories and sharing the locations of the satellites so scientists can plan their work.

The consequences would be dire

It remains to be seen whether Reflect Orbital’s project will get off the ground. The company may launch a test satellite, but it’s a long way from that to getting 250,000 enormous mirrors constantly circling Earth to keep some solar farms ticking over for a few extra hours a day.

Still, it’s a project to watch. The consequences of success for astronomers – and anyone else who likes the night sky dark – would be dire.

Michael J. I. Brown receives research funding from the Australian Research Council.

Matthew Kenworthy receives research funding from the Dutch Research Council (NWO).

– ref. A US startup plans to deliver ‘sunlight on demand’ after dark. Can it work – and would we want it to? – https://theconversation.com/a-us-startup-plans-to-deliver-sunlight-on-demand-after-dark-can-it-work-and-would-we-want-it-to-264323